Electroluminescent imidazo-quinoxaline carbene metal complexes

ABSTRACT

Metal carbene complexes comprising at least one imidazo-quinoxaline ligand, organic electronic devices, especially OLEDs (Organic Light-Emitting Diodes) which comprise such complexes, a light-emitting layer comprising at least one inventive metal carbene complex, an apparatus selected from the group consisting of illuminating elements, stationary visual display units and mobile visual display units comprising such an OLED, the use of such a metal carbene complex for electrophotographic photoreceptors, photoelectric converters, organic solar cells (organic photovoltaics), switching elements, organic light emitting field effect transistors (OLEFETs), image sensors, dye lasers and electroluminescent devices and a process for preparing such metal carbene complexes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage Application filed under 35U.S.C. § 371 of International Patent Application No. PCT/EP2015/068240,filed Aug. 7, 2015, which is entitled to priority under 35 U.S.C. §119(e) to European Application No. 14180422.9, filed Aug. 8, 2014, allof which applications are hereby incorporated by reference in theirentireties.

The present invention relates to metal-carbene complexes comprising atleast one imidazo-quinoxaline ligand of the general formula (I), toorganic electronic devices, especially OLEDs (Organic Light-EmittingDiodes) which comprise such complexes, to a light-emitting layercomprising at least one inventive metal carbene complex, to an apparatusselected from the group consisting of illuminating elements, stationaryvisual display units and mobile visual display units comprising such anOLED, to the use of such a metal-carbene complex for electrophotographicphotoreceptors, photoelectric converters, organic solar cells (organicphotovoltaics), switching elements, organic light emitting field effecttransistors (OLEFETs), image sensors, dye lasers and electroluminescentdevices and to a process for preparing such metal-carbene complexes.

Organic light-emitting diodes (OLEDs) exploit the propensity ofmaterials to emit light when they are excited by electrical current.OLEDs are of particular interest as an alternative to cathode ray tubesand liquid-crystal displays for production of flat visual display units.Owing to the very compact design and the intrinsically low powerconsumption, devices comprising OLEDs are suitable especially for mobileapplications, for example for applications in cellphones, smartphones,digital cameras, mp3 players, laptops, etc. In addition, white OLEDsgive great advantages over the illumination technologies known to date,especially a particularly high efficiency.

The prior art proposes numerous materials which emit light on excitationby electrical current.

WO2006/056418A2 discloses the use of “unsymmetrical” transitionmetal-carbene complexes comprising one aromatic ligand and one aliphaticligand connected with an imidazole ring in organic light-emittingdiodes. The imidazole ring may comprise further aromatic or non-aromaticrings fused to the imidazole ring. All complexes shown in the examplesin WO2006/056418A2 emit light in the purple to blue region of theelectromagnetic spectrum.

WO2011/073149A1 discloses metal complexes comprising diazabenzimidazolcarbene ligands and their use in OLEDs. According to the specification,metal complexes are provided emitting light especially in the blueregion of the electromagnetic spectrum. Diazabenzimidazole carbeneligands, wherein the benzimidazole residue comprises further fusedaromatic rings are excluded in WO2011/073149A1.

WO2012/170463 relates to metal-carbene complexes comprising a centralatom selected from iridium and platinum, and specificazabenzimidazolocarbene ligands and to OLEDs, which comprise suchcomplexes. WO2012/170461 and WO2012/121936 relate to metal-carbenecomplexes comprising a central atom selected from iridium and platinum,and diazabenzimidazolocarbene ligands, to organic light diodes whichcomprise such complexes and to light-emitting layers comprising at leastone such metal-carbene complex. However, no complexes which haveimidazo-quinoxaline carbene ligands are disclosed by said documents.

The carbene complexes mentioned in the prior art mentioned aboveare—according to said prior art—especially suitable as emitter materialsemitting light in the blue region of the visible electromagneticspectrum.

In the prior art mentioned below, complexes suitable as emittermaterials emitting light in the green region of the visibleelectromagnetic spectrum are mentioned.

Baldo et al., Applied Physics Letters, vol. 75, No. 1, 5 Jul. 1999, 4-6,concerns an organic light-emitting device based on electrophosphorescentemitting light in the green region of the electromagnetic spectrumcomprising—as emitter material—fac tris(2-phenylpyridine)iridium([Ir(ppy)₃]).

US2011/0227049A1 concerns organic iridium complexes containing a2-phenylpyridine ligand having a twisted aryl group on the pyridineportion of the ligand. The compounds may be used in organiclight-emitting devices, particularly as emitting dopants. The iridiumcompounds shown in US2011/0227049A1 are, according to all examples,employed as emitter material in organic light-emitting diodes emittinglight in the green region of the electromagnetic spectrum.

US2014/0203268A1 discloses heteroleptic iridium complexes having acombination of ligands which includes a single pyridyldibenzo-substituted ligand. The compounds may be used in organiclight-emitting devices. All organic light-emitting devices mentioned inthe examples of US2014/0203268A1 comprise the specific iridium complexesmentioned before as emitter materials emitting light in the green regionof the electromagnetic spectrum.

WO2012/053627A1 discloses organometallic complexes in which a4-arylpyrimidine derivative is a ligand and iridium is a central metal,which organometallic complex emits phosphorescence and may be used in alight-emitting device. According to the specification, theorganometallic complex has a broad range of emission spectra in thewavelength range of red to green.

One important application for phosphorescent emissive molecules is afull color display. Industry standards for such a display call forpixels adapted to emit the particular colors: saturated red, green andblue pixels. The color may be measured using CIE coordinates, which arewell-known to a person skilled in the art.

There is therefore a need to provide phosphorescent emissive moleculesemitting with high quantum efficiency and good color purity in the red,green and blue area of the electromagnetic spectrum.

Since highly emissive phosphorescent molecules emitting light in theblue region of the electromagnetic spectrum, based on carbene ligands,are known in the art (see for example the prior art mentioned above), itis an object of the present invention to provide phosphorescent emissivemolecules based on transition metal carbene complexes, emitting in thegreen to yellow region of the visible electromagnetic spectrum, i.e.having a λ_(max) of 510 to 590 nm. The preferred CIE-y coordinate ishigher than 0.47, preferably higher than 0.50.

It is a further object of the present invention to provide organicelectronic devices, preferably OLEDs, having—compared with the organicelectronic devices known in the art—a high color purity in the green toyellow region of the visible electromagnetic spectrum, a highefficiency, low voltage and/or improved lifetime/stability.

The object is achieved by a metal carbene complex, wherein the metal isselected from Ir and Pt, comprising at least one ligand of formula (A),preferably at least one ligand of formula (I)

preferably

whereinis NR^(x), O or S, preferably NR^(x) or O, more preferably NR^(x),R^(x) is

R¹, R², R³ and R⁴are independently of each other hydrogen; a C₁-C₁₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one of O, S andNR⁶⁵ and/or substituted by at least one substituent E; a C₆-C₁₄arylgroup, which can optionally be substituted by at least one substituentG; a —NR⁶⁵—C₆-C₁₄aryl group, preferably a —N(C₆-C₁₄aryl)₂ group, whichcan optionally be substituted by at least one substituent G; aheteroaryl group comprising 3 to 11 ring atoms, which can optionally besubstituted by at least one substituent G, interrupted by at least oneof O, S, N and NR⁶⁵; or a —NR⁶⁵-heteroaryl group, preferably a—N(heteroaryl)₂ group, comprising 3 to 11 ring atoms, which canoptionally be substituted by at least one substituent G, interrupted byat least one of O, S, N and NR⁶⁵; a halogen atom, especially F or Cl; aC₁-C₁₈haloalkyl group such as CF₃; CN; or SiR⁸⁰R⁸¹R⁸²;orR¹ and R², R² and R³ or R³ and R⁴ form together a ring

wherein A²¹, A^(21′), A²², A^(22′), A²³, A^(23′), A^(24′) and A²⁴ areindependently of each other H, a C₁-C₄alkyl group, a C₃-C₆cycloalkylgroup, or a fluoroC₁-C₄alkyl group;

R⁵ and R⁶

are independently of each other hydrogen; a C₁-C₁₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one of O, S andNR⁶⁵ and/or substituted by at least one substituent E; a C₆-C₁₄arylgroup, which can optionally be substituted by at least one substituentG; a —NR⁶⁵—C₆-C₁₄aryl group, preferably a —N(C₆-C₁₄aryl)₂ group, whichcan optionally be substituted by at least one substituent G; aheteroaryl group comprising 3 to 11 ring atoms, which can optionally besubstituted by at least one substituent G, interrupted by at least oneof O, S, N and NR⁶⁵; a halogen atom, especially F or Cl; aC₁-C₁₈haloalkyl group such as CF₃; CN; orSiR⁸⁰R⁸¹R⁸²;R⁷, R⁸, R⁹, R²⁷ and R²⁸are independently of each other hydrogen; a C₁-C₁₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one of O, S andNR⁶⁵ and/or substituted by at least one substituent E; a C₆-C₁₄arylgroup, which can optionally be substituted by at least one substituentG; a heteroaryl group comprising 3 to 11 ring atoms, which canoptionally be substituted by at least one substituent G, interrupted byat least one of O, S, N and NR⁶⁵ a halogen atom, especially F or Cl; aC₁-C₁₈haloalkyl group such as CF₃; CN; or SiR⁸⁰R⁸¹R⁸²; in addition tothe groups mentioned above, R⁸ may be a —NR⁶⁵—C₆-C₁₄aryl group,preferably a —N(C₆-C₁₄aryl)₂ group, which can optionally be substitutedby at least one substituent G; or a —NR⁶⁵-heteroaryl group, preferably a—N(heteroaryl)₂ group, comprising 3 to 11 ring atoms, which canoptionally be substituted by at least one substituent G, interrupted byat least one of O, S, N and NR⁶⁵;orR⁵ and R⁶ and/or R⁸ and R⁹ together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0;D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—,—CR⁶³═CR⁶⁴—, or —C≡C, preferably —O—, —S— or —NR⁶⁵—;E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, halogen,a C₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; preferably F; a C₁-C₈haloalkylgroup such as CF₃, or a C₁-C₈alkyl group;preferably, E is C₁-C₈alkyl, C₁-C₈alkoxy, CN, halogen, preferably F, orC₁-C₈haloalkyl, such as CF₃; more preferably E is C₁-C₈alkyl,C₁-C₈alkoxy, or C₁-C₈haloalkyl, such as CF₃;G is E; or an unsubstituted C₆-C₁₄aryl group; a C₆-C₁₄aryl group, whichis substituted by F, C₁-C₁₈alkyl, or C₁-C₁₈alkyl, which is substitutedby F and/or interrupted by O; an unsubstituted heteroaryl groupcomprising 3 to 11 ring atoms, interrupted by at least one of O, S, Nand NR⁶⁵; or a heteroaryl group comprising 3 to 11 ring atoms,interrupted by at least one of O, S, N and NR⁶⁵, which is substituted byF, unsubstituted C₁-C₁₈alkyl, SiR⁸⁰R⁸¹R⁸², or C₁-C₁₈alkyl which issubstituted by F and/or interrupted by O;preferably, G is a C₁-C₈alkyl group, or a group of formula

R^(a) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group,R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group,R^(c), R^(b) and R^(d) are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by G; a C₃-C₁₀heterocycloalkyl radical which is interruptedby at least one of O, S and NR⁶⁵ and/or substituted by E; a C₆-C₂₄arylgroup, which can optionally be substituted by G; or a C₂-C₃₀heteroarylgroup, which can optionally be substituted by G; a halogen atom,especially F or Cl; C₁-C₈haloalkyl such as CF₃; CN; or SiR⁸⁰R⁸¹R⁸²;orR^(c) and R^(b), or R^(a) and R^(b) together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0;R⁶³ and R⁶⁴ are independently of each other H; unsubstituted C₆-C₁₈aryl;C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy;unsubstituted C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—;preferably unsubstituted C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; unsubstituted C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—; R⁶⁵ and R⁶⁶ are independently of each otherH, an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;R⁶⁵ and R⁶⁶ together form a five or six membered ring,R⁶⁷ is H, an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;R⁶⁸ is H; an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;R⁶⁹ is H, an unsubstituted C₆-C₁₈aryl; a C₆-C₁₈aryl, which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably an unsubstituted C₆-C₁₈aryl; a C₆-C₁₈aryl, which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;R⁷⁰ and R⁷¹ are independently of each other an unsubstituted C₁-C₁₈alkylgroup; an unsubstituted C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl; R⁷² is an unsubstituted C₁-C₁₈alkylgroup; an unsubstituted C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl;R⁷³ and R⁷⁴ are independently of each other H, C₁-C₂₅alkyl, C₁-C₂₅alkylwhich is interrupted by O, C₇-C₂₅arylalkyl, C₆-C₂₄aryl, C₆-C₂₄aryl whichis substituted by C₁-C₁₈alkyl, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroarylwhich is substituted by C₁-C₁₈alkyl;R⁷⁵ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—;R⁸⁰, R⁸¹ and R⁸² are independently of each other a C₁-C₂₅alkyl group,which can optionally be interrupted by O; a C₆-C₁₄aryl group, which canoptionally be substituted by C₁-C₁₈alkyl; or a heteroaryl groupcomprising 3 to 11 ring atoms, which can optionally be substituted byC₁-C₁₈alkyl;˜ is a bonding site to the metal.

It has been found by the inventors of the present invention that theinventive metal carbene complexes mentioned above emit light in theyellow to green area, especially in the yellow-green to green region,respectively in the green to yellow area, especially in the green toyellow-green region, of the visible electromagnetic spectrum (λ_(max) of510 to 590 nm). It has been further found by the inventors of thepresent application—in contrast to the expectation of a person skilledin the art—that the imidazo-quinoxaline carbene metal complexesaccording to the present invention show a short lifetime of theluminescence (τ_(v)) of the respective Pt or Ir carbene complexes,especially Ir carbene complexes, of the present invention.

These metal-carbene complexes may spend less time in the excited state,thereby decreasing the possibility for photochemical reactions, orquenching to occur. Therefore, these compounds may provide devices withimproved stability and/or also improved device efficiency. In addition,the inventive metal-carbene complexes may provide reduced color-shift ofthe emission with increasing doping concentration of the compounds in ahost material.

Organic electronic devices comprising the metal carbene complexesaccording to the present invention further show a high color purity inthe green to yellow region, especially in the yellow-green to greenregion, respectively in the green to yellow-green region, of the visibleelectromagnetic spectrum, a high efficiency, low voltage and/or improvedlifetime/stability.

Organic electronic devices, preferably OLEDs, comprising themetal-carbene complex according to the present invention further showimproved device performance such as high quantum efficiency, highluminous efficacy, low voltage, good stabilities and/or long lifetimes.The inventive metal-carbene complexes comprising at least one ligand offormula (I) are particularly suitable as emitter materials with anemission in the green to yellow region of the visible electromagneticspectrum with a λ_(max) of 510 to 590 nm. The preferred CIE-y coordinateis higher than 0.47, preferably higher than 0.50. This enables forexample the production of white OLEDs, or full-color displays.

Any colour can be expressed by the chromaticity coordinates x and y onthe CIE chromaticity diagram. The boundaries of this horseshoe-shapeddiagram are the plots of monochromatic light, called spectrum loci, andall the colours in the visible spectrum fall within or on the boundaryof this diagram. The arc near the centre of the diagram is called thePlanckian locus, which is the plot of the coordinates of black bodyradiation at the temperatures from 1000 K to 20000 K, described as CCT.

The correlated colour temperature (CCT) is the temperature of ablackbody radiator that has a colour that most closely matches theemission from a nonblackbody radiator.

The metal carbene complexes of the present invention preferably emityellow to green light (λ_(max) of 510 to 590 nm) with a FWHM (full widthat half maximum) of 20 nm to 140 nm, more preferably of 40 nm to 100 nm,most preferably 60 nm to 90 nm.

In case of OLED display applications, the color purity plays a crucialrole. In order to achieve highly efficient displays with high colorgamut, it is reasonable that the spectra of the OLED emitters arenarrow. Therefore, it is preferred that the emission shows a single peakspectrum with a full width half-maximum (FWHM) of 20 nm to 140 nm, morepreferably of 40 nm to 100 nm, most preferably 60 nm to 90 nm. For OLEDlighting application, a broad spectrum is beneficial.

The triplet decay time (=lifetime of the luminescence τ_(v)) of metalcarbene complexes of the present invention (as emitter) is 0.5 to 100micro seconds, more preferably 0.5 to 10 micro seconds, most preferably0.5 to 5 micro seconds, even more preferably 0.5 to 3 micro seconds.

The metal carbene complex according to the present invention is—at roomtemperature (i.e. at 25° C.)—a phosphorescent emitter.

The phosphosphorescent emitters according to the present invention emitpreferably from triplet excited states. Phosphorescence may be precededby a transition from a triplet excited state to an intermediatenon-triplet state from which the emissive decay occurs. For example,organic molecules coordinated to lanthanide elements often phosphorescefrom excited states localized on the lanthanide metal. However, suchmaterials do not phosphoresce directly from a triplet excited state butinstead emit from an atomic excited state centered on the lanthanidemetal ion. The europium diketonate complexes illustrate one group ofthese types of species.

The absolute photoluminescence quantum yield of the metal carbenecomplexes of the present invention (measured at room temperature (in thecontext of the present invention “room temperature” is 25° C.)) is ingeneral at least 50%, preferably at least 70%, e.g. 50 to 95%, morepreferably 70 to 95%.

In a preferred embodiment, the absolute photoluminescence quantum yieldof the metal carbene complexes of the present invention (measured atroom temperature (in the context of the present invention “roomtemperature” is 25° C.)) is in general 50 to 99%, more preferably 70 to99%.

The determination of the photoluminescence spectra of the inventivemetal carbene complexes as well as the determination of the lifetime ofluminescence τ_(v) are described below. The further data mentioned belowcan be determined based on said information by methods known to a personskilled in the art.

Another advantage of the complexes according to the present invention istheir generally very high thermal stability. The complexes according tothe present invention generally remain undegraded at a temperature above250° C., preferably above 300° C., more preferably above 350° C., ingeneral for a duration of more than 2 days, preferably more than 5 days,more preferably more than 9 days. This can for example been proved by aso-called “ampulla test”. For that test, 50 mg of material have beensealed in glass ampullas under nitrogen atmosphere and afterwards theywere stored in an oven at different temperatures at temperatures between310° up to 385° C. for a duration of 10 days. After that period thematerials have been investigated by means of HPLC to check theirquality. The results show that the inventive complexes remainundegraded.

A variety of representations are used to depict the bonding inmetal-carbenes, including those in which a curved line is used toindicate partial multiple bonding between the carbene carbon and theadjacent heteroatom(s):

preferably

In the figures and structures herein, a metal-carbene bond is depictedas C-M, as, for example,

preferably

The residues mentioned in the specification of the present applicationgenerally have the following preferred meanings, if not defineddifferently in a specific residue:

A C₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D: preferably a C₁-C₁₂alkyl group,which can optionally be substituted by at least one substituent E and/orinterrupted by D; more preferably a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; most preferably a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E; even morepreferably an unsubstituted C₁-C₈alkyl group; further even morepreferably an unsubstituted C₁-C₅alkyl group, e.g. methyl, ethyl,propyl, like n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl,tert-butyl, or neopentyl. The alkyl groups may be linear or branched.

A C₃-C₁₂cycloalkyl group, which can optionally be substituted by atleast one substituent E: preferably a C₃-C₁₂cycloalkyl group, which canoptionally be substituted by at least one substituent E; more preferablya C₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; most preferably an unsubstituted C₃-C₆cycloalkylgroup, e.g. cyclohexyl or cyclopentyl.

A heterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one of O, S and NR⁶⁵ and/or substituted by at least onesubstituent E: preferably an unsubstituted heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one of O, S andNR⁶⁵, e.g. heterocycloalkyl groups based on pyrrolidine,tetrahydrothiophene, tetrahydrofurane, tetrahydropyrane,tetrahydrothiopyrane, piperidine, dioxane, e.g. 1,4-dioxane ormorpholine and derivatives thereof substituted by at least onesubstituent E.

A C₆-C₁₄aryl group, which can optionally be substituted by at least onesubstituent G: preferably a C₆-C₁₄aryl group, which can optionally besubstituted by one or two groups G; more preferably a phenyl group,which can optionally be substituted by one or two groups G.

A —NR⁶⁵—C₆-C₁₄aryl group, which can optionally be substituted by atleast one substituent G: preferably a —N(C₆-C₁₄aryl)₂ group, which canoptionally be substituted by at least one substituent G; more preferablya —N(phenyl)₂ group, which can optionally be substituted by one or twogroups G; most preferably an unsubstituted—N(phenyl)₂ group.

A heteroaryl group comprising 3 to 11 ring atoms, which can optionallybe substituted by at least one substituent G, interrupted by at leastone of O, S, N and NR⁶⁵: preferably a heteroaryl group comprising 3 to11 ring atoms, which can optionally be substituted by one or two groupsG, interrupted by at least one of O, S, N and NR⁶⁵; more preferablypyridyl, methylpyridyl, pyrimidyl, pyrazinyl, carbazolyl,dibenzofuranyl, dibenzothiophenyl, indolyl, methylindolyl, benzofuranyland benzothiophenyl, which can optionally be substituted by one, or moregroups selected from a C₁-C₅alkyl group, a C₃-C₆cycloalkyl group and aC₁-C₄fluoroalkyl group; especially carbazolyl, dibenzofuranyl,dibenzothiophenyl, which can optionally be substituted by one, or moregroups selected from a C₁-C₅alkyl group, a C₃-C₆cycloalkyl group and aC₁-C₄fluoroalkyl group; more especially dibenzofuranyl,dibenzothiophenyl, which can optionally be substituted by one, or moregroups selected from a C₁-C₄alkyl group, and a C₃-C₆cycloalkyl group.

A a —NR⁶⁵-heteroaryl group, comprising 3 to 11 ring atoms, which canoptionally be substituted by at least one substituent G, interrupted byat least one of O, S, N and NR⁶⁵: preferably a —N(heteroaryl)₂ group,comprising 3 to 11 ring atoms, which can optionally be substituted by atleast one substituent G, interrupted by at least one of O, S, N andNR⁶⁵, preferred heteroaryl residues are mentioned before.

A halogen atom: preferably F or Cl, more preferably F.

A C₁-C₁₈haloalkyl group; preferably a fluoroC₁-C₄alkyl group, morepreferably CF₃. The alkyl groups may be linear or branched.

In the alkyl groups and aryl groups mentioned in the present applicationone or more hydrogen atoms may be substituted by deuterium atoms.

Metal Carbene Complexes According to the Present Invention

The residues R¹, R², R³ and R⁴ in the metal carbene complexes accordingto the present invention are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₁₂cycloalkyl group, whichcan optionally be substituted by at least one substituent E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one of O, S and NR⁶⁵ and/or substituted by at least onesubstituent E; a C₆-C₁₄aryl group, which can optionally be substitutedby at least one substituent G; a —NR⁶⁵—C₆-C₁₄aryl group, preferably a—N(C₆-C₁₄aryl)₂ group, which can optionally be substituted by at leastone substituent G; a heteroaryl group comprising 3 to 11 ring atoms,which can optionally be substituted by at least one substituent G,interrupted by at least one of O, S, N and NR⁶⁵; or a —NR⁶⁵-heteroarylgroup, preferably a —N(heteroaryl)₂ group, comprising 3 to 11 ringatoms, which can optionally be substituted by at least one substituentG, interrupted by at least one of O, S, N and NR⁶⁵; a halogen atom,especially F or Cl; a C₁-C₁₈haloalkyl group such as CF₃; CN; orSiR⁸⁰R⁸¹R⁸²;

or

R¹ and R², R² and R³ or R³ and R⁴ form together a ring

wherein A²¹, A^(21′), A²², A^(22′), A²³, A^(23′), A^(24′) and A²⁴ areindependently of each other H, a C₁-C₄alkyl group, a C₃-C₆cycloalkylgroup, or a fluoroC₁-C₄alkyl group.

Preferably, R¹, R², R³ and R⁴ are independently of each other hydrogen;a C₁-C₁₂alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₁₂cycloalkyl group, whichcan optionally be substituted by at least one substituent E; aC₆-C₁₄aryl group, which can optionally be substituted by one or twogroups G; a heteroaryl group comprising 3 to 11 ring atoms, which canoptionally be substituted by one or two groups G; or a —N(phenyl)₂group, which can optionally be substituted by one or two groups G.

More preferably, R¹, R², R³ and R⁴ are independently of each otherhydrogen; a C₁-C₈alkyl group, which can optionally be substituted by atleast one substituent E and/or interrupted by D; a C₃-C₆cycloalkylgroup, which can optionally be substituted by at least one substituentE; or a phenyl group, which can optionally be substituted by one or twogroups G.

Most preferably, R¹, R², R³ and R⁴ are independently of each otherhydrogen; a C₁-C₈alkyl group, which can optionally be substituted by atleast one substituent E; a C₃-C₆cycloalkyl group, which can optionallybe substituted by at least one substituent E; or a phenyl group, whichcan optionally be substituted by one or two groups G.

Even more preferably, R¹, R², R³ and R⁴ are independently of each otherhydrogen; a C₁-C₈alkyl group, which can optionally be substituted by atleast one substituent E; a C₃-C₆cycloalkyl group; or either R² and R³ orR¹ and R⁴ are a phenyl group, which can optionally be substituted by oneor two groups G.

Further more preferably, R¹, R², R³ and R⁴ are independently of eachother hydrogen; a C₁-C₈alkyl group; or a C₃-C₆cycloalkyl group.

In one especially preferred embodiment, either R² and R³ or R¹ and R⁴are H.

Further more preferably, R¹ and R⁴ are hydrogen and R² and R³ areindependently of each other hydrogen; a C₁-C₈alkyl group; or aC₃-C₆cycloalkyl group, or a phenyl group, which can optionally besubstituted by one or two groups G.

Most preferably, R¹, R², R³ and R⁴ are hydrogen.

The residues R⁵ and R⁶ are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₁₂cycloalkyl group, whichcan optionally be substituted by at least one substituent E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one of O, S and NR⁶⁵ and/or substituted by at least onesubstituent E; a C₆-C₁₄aryl group, which can optionally be substitutedby at least one substituent G; a —NR⁶⁵—C₆-C₁₄aryl group, preferably a—N(C₆-C₁₄aryl)₂ group, which can optionally be substituted by at leastone substituent G; a heteroaryl group comprising 3 to 11 ring atoms,which can optionally be substituted by at least one substituent G,interrupted by at least one of O, S, N and NR⁶⁵; a halogen atom,especially F or Cl; a C₁-C₁₈haloalkyl group such as CF₃; CN; orSiR⁸⁰R⁸¹R⁸²;

or

R⁵ and R⁶ together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0;D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—,—CR⁶³═CR⁶⁴—, or —C≡C, preferably —O—, —S— or —NR⁶⁵—.

Preferably, R⁵ and R⁶ are independently of each other hydrogen; aC₁-C₁₂alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by E;

or

one of R⁵ and R⁶, preferably R⁵, is a group of formula

in a further preferred embodiment, R⁶ is a group of formula

R^(a) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably H, a C₁-C₅alkyl group, C₃-C₆cycloalkylgroup; more preferably H, or a C₁-C₅alkyl group;R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably H, a C₁-C₅alkyl group, C₃-C₆cycloalkylgroup; more preferably H, or a C₁-C₅alkyl group;R^(c), R^(b) and R^(d) are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by G; a C₆-C₁₄aryl group, which can optionally besubstituted by G; or a C₂-C₃₀heteroaryl group, which can optionally besubstituted by G; C₁-C₈haloalkyl such as CF₃; or SiR⁸⁰R⁸¹R⁸²; preferablyR^(c), R^(b) and R^(d) are independently of each other H, a C₁-C₅alkylgroup, C₃-C₆cycloalkyl group; more preferably H, or a C₁-C₅alkyl group;further preferably, R^(b), R^(c) and R^(d) are hydrogen or a phenylgroup, which can optionally be substituted by one or two groups G;orR^(c) and R^(b), or R^(a) and R^(b) together form a group of formula

wherein Z is N or CR′″,wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0.

More preferably, R⁵ and R⁶ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; or one of R⁵ and R⁶ is aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or one of R⁵ and R⁶ is a phenyl group, which canoptionally be substituted by one or two groups G.

Most preferably, R⁵ and R⁶ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E; or a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent E; or a phenyl group, which canoptionally be substituted by one or two groups G.

Even more preferably, R⁵ and R⁶ are independently of each otherhydrogen; a C₁-C₈alkyl group, which can optionally be substituted by atleast one substituent E; a C₃-C₆cycloalkyl group, which can optionallybe substituted by at least one substituent E; or either R⁵ or R⁶,preferably R⁵, is a phenyl group, which can optionally be substituted byone or two groups G; in a further preferred embodiment R⁶ is a phenylgroup, which can optionally be substituted by one or two groups G.

Further more preferably, R⁵ and R⁶ are independently of each otherhydrogen; a C₁-C₈alkyl group; or a C₃-C₆cycloalkyl group. Preferably, atleast one of R⁵ and R⁶ is hydrogen, and the other one is a C₁-C₈alkylgroup. More preferably, at least R⁵ is hydrogen, and R⁶ is a C₁-C₈alkylgroup. Most preferably both R⁵ and R⁶ are hydrogen.

In one further preferred embodiment, R⁵ and R⁶ are independently of eachother hydrogen; a C₁-C₈alkyl group; or one of R⁵ and R⁶, preferably R⁵,is a phenyl group, which can optionally be substituted by one group ortwo groups selected from CF₃ or C₁-C₈alkyl, preferably optionally besubstituted by one or two C₁-C₈alkyl group; in a further preferredembodiment R⁶ is a phenyl group, which can optionally be substituted byone group or two groups selected from CF₃ or C₁-C₈alkyl, preferablyoptionally be substituted by one or two C₁-C₈alkyl group; preferably, atleast one of R⁵ and R⁶ is hydrogen; more preferably, at least one of R⁵and R⁶ is hydrogen and the other one of R⁵ and R⁶ is hydrogen or aphenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups.

Most preferably, R⁵ and R⁶ are hydrogen.

In a further embodiment, R⁵ is H and R⁶ is a phenyl group, which canoptionally be substituted by one group or two C₁-C₈alkyl groups.

R⁷, R⁸, R⁹, R²⁷ and R²⁸ are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₁₂cycloalkyl group, whichcan optionally be substituted by at least one substituent E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one of O, S and NR⁶⁵ and/or substituted by at least onesubstituent E; a C₆-C₁₄aryl group, which can optionally be substitutedby at least one substituent G; a heteroaryl group comprising 3 to 11ring atoms, which can optionally be substituted by at least onesubstituent G, interrupted by at least one of O, S, N and NR⁶⁵ a halogenatom, especially F or Cl; a C₁-C₁₈haloalkyl group such as CF₃; CN; orSiR⁸⁰R⁸¹R⁸²; in addition to the groups mentioned above, R⁸ may be a—NR⁶⁵—C₆-C₁₄aryl group, preferably a —N(C₆-C₁₄aryl)₂ group, which canoptionally be substituted by at least one substituent G; or a—NR⁶⁵-heteroaryl group, preferably a —N(heteroaryl)₂ group, comprising 3to 11 ring atoms, which can optionally be substituted by at least onesubstituent G, interrupted by at least one of O, S, N and NR⁶⁵;

or

R⁸ and R⁹ together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0;D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—,—CR⁶³═CR⁶⁴—, or —C≡C, preferably —O—, —S— or —NR⁶⁵—.

Preferably, R⁷, R⁸ and R⁹ are independently of each other hydrogen; aC₁-C₁₂alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by E, a C₆-C₁₄aryl group, which can optionally besubstituted by one or two groups G; a heteroaryl group comprising 3 to11 ring atoms, which can optionally be substituted by one or two groupsG.

Preferably, R²⁷, R²⁸ are independently of each other hydrogen; or aC₁-C₁₂alkyl group, which can optionally be substituted by E and/orinterrupted by D, preferably a CH₂—C₁-C₇alkyl group, which canoptionally be substituted by E and/or interrupted by D.

More preferably, R⁷, R⁸ and R⁹ are independently of each other hydrogen;a C₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₆cycloalkyl group, whichcan optionally be substituted by at least one substituent E or a phenylgroup, which can optionally be substituted by one or two groups G.

More preferably, at least one of R²⁷ and R²⁸ is hydrogen.

Most preferably, R⁷, R⁸ and R⁹ are independently of each other hydrogen;a C₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E; or a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent E; or a phenyl group, which canoptionally be substituted by one or two groups G.

Most preferably, R²⁷ and R²⁸ are hydrogen.

Even more preferably, R⁷, R⁸ and R⁹ are independently of each otherhydrogen; a C₁-C₈alkyl group, which can optionally be substituted by atleast one substituent E; a C₃-C₆cycloalkyl group; or R⁸ is a phenylgroup, which can optionally be substituted by one or two groups G.

Further more preferably, R⁷, R⁸ and R⁹ are independently of each otherhydrogen; a C₁-C₈alkyl group; or a C₃-C₆cycloalkyl group; mostpreferably, R⁷, R⁸ and R⁹ are a C₁-C₈alkyl group.

Further more preferably, R⁷ is hydrogen and R⁸ and R⁹ are identical withR⁵ and R⁶.

Most preferably, R⁷ and R⁹ are hydrogen and R⁸ is hydrogen or a phenylgroup, which can optionally be substituted by one or two groups G.

Even most preferably, R⁷, R⁸ and R⁹ are hydrogen.

In a most preferred embodiment, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR²⁷ and R²⁸ are hydrogen.

D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—,—CR⁶³═CR⁶⁴—, or —C≡C, preferably —O—, —S— or —NR⁶⁵—; more preferably—S—, or —O—;

E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, halogen,or a C₁-C₁₈alkyl group, which can optionally be substituted by at leastone substituent E and/or interrupted by D;

preferably F; a C₁-C₈haloalkyl group such as CF₃, or a C₁-C₈alkyl group;preferably, E is C₁-C₈alkyl, C₁-C₈alkoxy, CN, halogen, preferably F, orC₁-C₈haloalkyl, such as CF₃; more preferably E is C₁-C₈alkyl,C₁-C₈alkoxy, or C₁-C₈haloalkyl, such as CF₃; more preferably, E is—OR⁶⁹, CF₃, C₁-C₈alkyl or F; most preferably CF₃, C₁-C₈alkyl or F; evenmost preferably, E is —C₁-C₈alkyl.G is E; or an unsubstituted C₆-C₁₄aryl group; a C₆-C₁₄aryl group, whichis substituted by F, C₁-C₁₈alkyl, a C₃-C₆cycloalkyl group, orC₁-C₁₈alkyl, which is substituted by F and/or interrupted by O; anunsubstituted heteroaryl group comprising 3 to 11 ring atoms,interrupted by at least one of O, S, N and NR⁶⁵; or a heteroaryl groupcomprising 3 to 11 ring atoms, interrupted by at least one of O, S, Nand NR⁶⁵, which is substituted by F, unsubstituted C₁-C₁₈alkyl,SiR⁸⁰R⁸¹R⁸², or C₁-C₁₈alkyl which is substituted by F and/or interruptedby O;preferably, G is a C₁-C₈alkyl group, or a group of formula

R^(a) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group, preferably R^(a) H, a C₁-C₅alkyl group,C₃-C₆cycloalkyl group; more preferably, R^(a) is H, or a C₁-C₅alkylgroup;R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably R^(e) H, a C₁-C₅alkyl group,C₃-C₆cycloalkyl group; more preferably, R^(e) is H, or a C₁-C₅alkylgroup;R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group;R^(c), R^(b) and R^(d) are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by G; a C₃-C₁₀heterocycloalkyl radical which is interruptedby at least one of O, S and NR⁶⁵ and/or substituted by E; a C₆-C₂₄arylgroup, which can optionally be substituted by G;or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; ahalogen atom, especially F or Cl; C₁-C₈haloalkyl such as CF₃; CN; orSiR⁸⁰R⁸¹R⁸²; preferably R^(c), R^(b) and R^(d) are independently of eachother H, a C₁-C₅alkyl group, C₃-C₆cycloalkyl group; more preferably,R^(c), R^(b) and R^(d) are independently of each other H, or aC₁-C₅alkyl group;orR^(c) and R^(b), or R^(a) and R^(b) together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0; more preferably, Gis —OR⁶⁹, CF₃ or C₁-C₈alkyl; most preferably, G is CF₃ or C₁-C₈alkyl;even more preferably, G is C₁-C₈alkyl.

R⁶³ and R⁶⁴ are independently of each other H; unsubstituted C₆-C₁₈aryl;C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy;unsubstituted C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—;preferably unsubstituted C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; unsubstituted C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—;

preferably, R⁶³ and R⁶⁴ are independently of each other a phenyl group,which can optionally be substituted by one or two C₁-C₈alkyl groups; anunsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—.

R⁶⁵ and R⁶⁶ are independently of each other H, an unsubstitutedC₆-C₁₈aryl group; a C₆-C₁₈aryl group which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstituted C₁-C₁₈alkyl group; or aC₁-C₁₈alkyl group, which is interrupted by —O—; or R⁶⁵ and R⁶⁶ togetherform a five or six membered ring; preferably, R⁶⁵ and R⁶⁶ areindependently of each other a phenyl group, which can optionally besubstituted by one or two C₁-C₈alkyl groups; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—.

R⁶⁷ is H, an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably, R⁶⁷ is a phenyl group, which can optionally be substitutedby one or two C₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; ora C₁-C₁₈alkyl group, which is interrupted by —O—.

R⁶⁸ is H; an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably, R⁶⁸ is a phenyl group, which can optionally be substitutedby one or two C₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; ora C₁-C₁₈alkyl group, which is interrupted by —O—.

R⁶⁹ is H, an unsubstituted C₆-C₁₈aryl; a C₆-C₁₈aryl, which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably an unsubstituted C₆-C₁₈aryl; a C₆-C₁₈aryl, which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;preferably, R⁶⁹ is a phenyl group, which can optionally be substitutedby one or two C₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; ora C₁-C₁₈alkyl group, which is interrupted by —O—.

R⁷⁰ and R⁷¹ are independently of each other an unsubstituted C₁-C₁₈alkylgroup; an unsubstituted C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, whichis substituted by C₁-C₁₈alkyl; preferably, R⁷⁰ and R⁷¹ are independentlyof each other a phenyl group, which can optionally be substituted by oneor two C₁-C₈alkyl groups; or an unsubstituted C₁-C₁₈alkyl group.

R⁷² is an unsubstituted C₁-C₁₈alkyl group; an unsubstituted C₆-C₁₈arylgroup, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl;preferably, R⁷² is a phenyl group, which can optionally be substitutedby one or two C₁-C₈alkyl groups; or an unsubstituted C₁-C₁₈alkyl group.

R⁷³ and R⁷⁴ are independently of each other H, C₁-C₂₅alkyl, C₁-C₂₅alkylwhich is interrupted by O, C₇-C₂₅arylalkyl, C₆-C₂₄aryl, C₆-C₂₄aryl whichis substituted by C₁-C₁₈alkyl, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroarylwhich is substituted by C₁-C₁₈alkyl; preferably, R⁷³ and R⁷⁴ areindependently of each other a phenyl group, which can optionally besubstituted by one or two C₁-C₈alkyl groups; an unsubstitutedC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—.

R⁷⁵ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C¹-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; preferably, R⁷⁵ is a phenyl group,which can optionally be substituted by one or two C₁-C₈alkyl groups; anunsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—.

R⁸⁰, R⁸¹ and R⁸² are independently of each other a C₁-C₂₅alkyl group,which can optionally be interrupted by O; a C₆-C₁₄aryl group, which canoptionally be substituted by C₁-C₁₈alkyl; or a heteroaryl groupcomprising 3 to 11 ring atoms, which can optionally be substituted byC₁-C₁₈alkyl; preferably, R⁸⁰, R⁸¹ and R⁸² are independently of eachother a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—.

In a preferred embodiment the present invention concerns the inventivemetal carbene complex, wherein at least one of the radicals R¹, R², R³,R⁴, R⁵, R⁶, R⁷, R⁸, and R⁹ is not hydrogen; preferably, either R⁵ is nothydrogen or at least two of the radicals R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸and R⁹ are not hydrogen.

In a further preferred embodiment two adjacent radicals of the group R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ are not at the same time anaromatic group, e.g. a C₆-C₁₄aryl group, which can optionally besubstituted by at least one substituent G; a —NR⁶⁵—C₆-C₁₄aryl group,preferably a —N(C₆-C₁₄aryl)₂ group, which can optionally be substitutedby at least one substituent G; a heteroaryl group comprising 3 to 11ring atoms, which can optionally be substituted by at least onesubstituent G, interrupted by at least one of O, S, N and NR⁶⁵; or a—NR⁶⁵-heteroaryl group, preferably a —N(heteroaryl)₂ group, comprising 3to 11 ring atoms, which can optionally be substituted by at least onesubstituent G, interrupted by at least one of O, S, N and NR⁶⁵.

The present invention also concerns a combination of both preferredembodiments mentioned before.

In a most preferred embodiment, the present invention concerns theinventive metal carbene complex, wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸,R⁹ and R²⁷ and R²⁸ are hydrogen.

In the case that R⁶ and R⁸ are both present in the inventive metalcarbene complexes, R⁶ and R⁸ are preferably identical.

In the case that R⁵ and R⁹ are both present in the inventive metalcarbene complexes, R⁵ and R⁹ are identical. “Present” means in the senseof the present application that the respective residues are nothydrogen.

The metal carbene complex according to the present invention ispreferably an inventive metal carbene complex, wherein

R¹, R², R³ and R⁴

are independently of each other hydrogen; a C₁-C₁₂alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a C₆-C₁₄aryl group, which canoptionally be substituted by one or two groups G; a heteroaryl groupcomprising 3 to 11 ring atoms, which can optionally be substituted byone or two groups G; or a —N(phenyl)₂ group, which can optionally besubstituted by one or two groups G;preferably, R¹, R², R³ and R⁴ are independently of each other hydrogen;a C₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₆cycloalkyl group, whichcan optionally be substituted by at least one substituent E; or a phenylgroup, which can optionally be substituted by one or two groups G; morepreferably, R¹, R²,R³ and R⁴ are hydrogen;R⁵ and R⁶are independently of each other hydrogen; a C₁-C₁₂alkyl group, which canoptionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by E;orone of R⁵ and R⁶, preferably R⁵, is a group of formula

in a further preferred embodiment R⁶ is a group of formula;R^(a) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably H, a C₁-C₅alkyl group, C₃-C₆cycloalkylgroup; more preferably H, or a C₁-C₅alkyl group;R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably H, a C₁-C₅alkyl group, C₃-C₆cycloalkylgroup; more preferably H, or a C₁-C₅alkyl group;R^(c), R^(b) and R^(d) are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by G; a C₆-C₁₄aryl group, which can optionally besubstituted by G; or a C₂-C₃₀heteroaryl group, which can optionally besubstituted by G; C₁-C₈haloalkyl such as CF₃; orSiR⁸⁰R⁸¹R⁸²; preferably R^(c), R^(b) and R^(d) are independently of eachother H, a C₁-C₅alkyl group, C₃-C₆cycloalkyl group; more preferably H,or a C₁-C₅alkyl group; further preferably R^(c), R^(b) and R^(d) arehydrogen or a phenyl group which can optionally substituted by one ortwo groups G;orR^(c) and R^(b), or R^(a) and R^(b) together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C1-C8alkyl anda is 0, 1 or 2, preferably 0 or 1, more preferably 0;preferably, R⁵ and R⁶ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; or one of R⁵ and R⁶ is aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or one of R⁵ and R⁶ is a phenyl group, which canoptionally be substituted by one or two groups G; more preferably, R⁵and R⁶ are hydrogen;R⁷, R⁸ and R⁹are independently of each other hydrogen; a C₁-C₁₂alkyl group, which canoptionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by E aC₆-C₁₄aryl group, which can optionally be substituted by one or twogroups G; a heteroaryl group comprising 3 to 11 ring atoms, which canoptionally be substituted by one or two groups G;preferably, R⁷, R⁸ and R⁹ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₆cycloalkyl group, whichcan optionally be substituted by at least one substituent E; morepreferably, R⁷ and R⁹ are hydrogen and R⁸ is hydrogen or a phenyl groupwhich can be optionally substituted by one or two groups G; mostpreferably, R⁷, R⁸ and R⁹ are hydrogen;R²⁷, R²⁸are independently of each other hydrogen; a C₁-C₁₂alkyl group, which canoptionally be substituted by E and/or interrupted by D, preferably aCH₂—C₁-C₇alkyl group, which can optionally be substituted by E and/orinterrupted by D;preferably, at least one of R²⁷ and R²⁸ is hydrogen, more preferably,R²⁷ and R²⁸ are hydrogen;D is —S—, or —O—E is —OR⁶⁹, CF₃, C₁-C₈alkyl or F; preferably CF₃, C₁-C₈alkyl or F; mostpreferably C₁-C₈alkyl;G is —OR⁶⁹, CF₃ or C₁-C₈alkyl; preferably CF₃ or C₁-C₈alkyl; morepreferably C₁-C₈alkyl;R⁶⁵ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; andR⁶⁹ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—.

More preferably, the metal carbene complex according to the presentinvention is an inventive metal carbene complex, wherein

R¹, R², R³ and R⁴

are independently of each other hydrogen; a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E; aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G;preferably, R¹, R², R³ and R⁴ are independently of each other hydrogen;a C₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E; a C₃-C₆cycloalkyl group; or either R² and R³ or R¹ and R⁴are a phenyl group, which can optionally be substituted by one or twogroups G; more preferably, R¹, R², R³ and R⁴ are hydrogen;R⁵ and R⁶are independently of each other hydrogen; a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G;preferably, R⁵ and R⁶ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E; a C₃-C₆cycloalkyl group; or either R⁵ or R⁶, preferablyR⁵, is a phenyl group, which can optionally be substituted by one or twogroups G; in a further preferred embodiment, R⁶ is a phenyl group, whichcan optionally be substituted by one or two groups G; more preferably,R⁵ and R⁶ are hydrogen;R⁷, R⁸ and R⁹are independently of each other hydrogen; a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G;preferably, R⁷, R⁸ and R⁹ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E; a C₃-C₆cycloalkyl group; or R⁸ is a phenyl group, whichcan optionally be substituted by one or two groups G; more preferably,R⁷ and R⁹ are hydrogen and R⁸ is hydrogen or a phenyl group which can beoptionally substituted by one or two groups G; most preferably, R⁷, R⁸and R⁹ are hydrogen;R²⁷ and R²⁸are hydrogen;E is CF₃, C₁-C₈alkyl or F; preferably, E is C₁-C₈alkyl;G is CF₃ or C₁-C₈alkyl; preferably C₁-C₈alkyl;R⁶⁵ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkylgroup, which is interrupted by —O—; andR⁶⁹ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkylgroup, which is interrupted by —O—.

Most preferably, the metal carbene complex according to the presentinvention is an inventive metal carbene complex, wherein

R¹, R², R³ and R⁴

are independently of each other hydrogen; a C₁-C₈alkyl group; or aC₃-C₆cycloalkyl group; or either R¹ and R⁴ or R² and R³ are a phenylgroup, which can optionally be substituted by one or two groups G;preferably, R¹ and R⁴ are hydrogen and R² and R³ are are independentlyof each other hydrogen; a C₁-C₈alkyl group; or a C₃-C₆cycloalkyl group,or a phenyl group, which can optionally be substituted by one or twogroups G.

Further most preferably, R¹, R², R³ and R⁴ are hydrogen.

R⁵, R⁶, R⁷, R⁸ and R⁹

are independently of each other hydrogen; a C₁-C₈alkyl group; or aC₃-C₆cycloalkyl group; or R⁷ and R⁹ are hydrogen and R⁸ is hydrogen or aphenyl group which can be optionally substituted by one or two groups Gand either one of R⁵ and R⁶ is phenyl group which can be optionallysubstituted by one or two groups G and the other one of R⁵ and R⁶ ishydrogen; more preferably, R⁵, R⁶, R⁷, R⁸ and R⁹ are hydrogen;andR²⁷ and R²⁸are hydrogen.

Even more preferably, the metal carbene complex according to the presentinvention is an inventive metal carbene complex, wherein

either R² and R³ or R¹ and R⁴ are H; preferably, R¹ and R⁴ are H, morepreferably, R¹, R², R³ and R⁴ are H.

Further more preferably, the metal carbene complex according to thepresent invention is an inventive metal carbene complex, wherein

R⁵ and R⁶

are independently of each other hydrogen; a C₁-C₈alkyl group; or one ofR⁵ and R⁶, preferably R⁵, is a phenyl group, which can optionally besubstituted by one or two groups selected from CF₃ or C₁-C₈alkyl,preferably optionally be substituted by one or two C₁-C₈alkyl groups;preferably, at least one of R⁵ and R⁶ is hydrogen; more preferably, R⁵and R⁶ are hydrogen;R⁷ and R⁹are C₁-C₈alkyl or R⁷ and R⁹ are hydrogen; preferably, R⁷ and R⁹ arehydrogen; R⁸is hydrogen; a C₁-C₈alkyl group; or a phenyl group, which can optionallybe para-substituted by one group selected from CF₃ or C₁-C₈alkyl,preferably optionally be substituted by one C₁-C₈alkyl group;preferably, R⁸ is hydrogen;R²⁷ and R²⁸are hydrogen.

In a further embodiment of the present invention, the metal carbenecomplex according to the present invention is further more preferably aninventive metal carbene complex, wherein

R⁵

is hydrogen; a C₁-C₈alkyl group, which can optionally be substituted byat least one substituent selected from CF₃, C₁-C₈alkyl and F, preferablya C₁-C₈alkyl substituent; a C₃-C₆cycloalkyl group, which can optionallybe substituted by at least one substituent selected from CF₃, C₁-C₈alkyland F, preferably a C₁-C₈alkyl substituent; or a phenyl group, which canoptionally be substituted by one or two groups selected from CF₃ andC₁-C₈alkyl, preferably optionally be substituted by one or twoC₁-C₈alkyl groups; preferably hydrogen;R⁶ and R⁸are identical and selected from the group consisting of a C₁-C₈alkylgroup, which can optionally be substituted by at least one substituentselected from CF₃, C₁-C₈alkyl and F, preferably a C₁-C₈alkylsubstituent; a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent selected from CF₃, C₁-C₈alkyland F, preferably a C₁-C₈alkyl substituent; and a phenyl group, whichcan optionally be substituted by one or two groups selected from CF₃ andC₁-C₈alkyl, preferably optionally be substituted by one or twoC₁-C₈alkyl groups; preferably hydrogen;andR⁷ and R⁹are hydrogen,wherein R⁵ and R⁶ are not at the same time a phenyl group, which canoptionally be substituted by one or two groups selected from CF₃ andC₁-C₈alkyl, preferably optionally be substituted by one or twoC₁-C₈alkyl groups;R²⁷ and R²⁸are hydrogen.

In a further embodiment of the present invention, the metal carbenecomplex according to the present invention is further more preferably aninventive metal carbene complex, wherein

R⁷, R⁸ and R⁹ are H; and

R⁶ is H; and

R²⁷ and R²⁸

are hydrogen.

Preferably, the metal carbene complex according to the present inventionhas the following formula (B), preferably the following formula (II)

preferably

whereinis NR^(x), O or S, preferably NR^(x) or O, more preferably R^(x);R^(x) is

M is Pt, or Ir, preferably Ir;if M is Ir, m is 1, 2, or 3, preferably 2 or 3; o is 0, 1, or 2,preferably 0 or 1; and the sum of m+o is 3;in the case that o=2, the ligands L may be the same or different,preferably the same; and in the case that m is 2 or 3, the m carbeneligands may be the same or different, preferably the same;if M is Pt, m is 1, or 2; o is 0, or 1; and the sum of m+o is 2;in the case that m is 2, the m carbene ligands may be the same ordifferent, preferably the same; andL is a monoanionic bidentate ligand;and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ having the meaningsmentioned before.

Preferably, the metal carbene complex according to the present inventionhas the formula (II).

More preferably, the residues, symbols and indices in the metal carbenecomplex of formula (II) according to the present invention have thefollowing meanings:

M is Ir;

m is 2 or 3; o is 0 or 1; and the sum of m+o is 3;

in the case that o=2, the ligands L may be the same or different,preferably the same; and in the case that m is 2 or 3, the m carbeneligands may be the same or different, preferably the same; and

L is a monoanionic bidentate ligand;

and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ having the meaningsmentioned before.

In one most preferred embodiment, the metal carbene complex according tothe present invention has the formula (B), preferably the formula (II)mentioned above wherein

is NR^(x), O or S, preferably NR^(x) or O, more preferably NR^(x);

R^(x) is

M is Ir;m is 1; o is 2, wherein the ligands L may be the same or different,preferably the same; andL is a monoanionic bidentate ligand;and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ having the meaningsmentioned before.

In another most preferred embodiment, the metal carbene complexaccording to the present invention has the formula (B), preferably theformula (II) mentioned above

wherein

is NR^(x), O or S, preferably NR^(x) or O, more preferably NR^(x);

R^(x) is

M is Ir;m is 2; o is 1, wherein the m carbene ligands may be the same ordifferent, preferably the same; andL is a monoanionic bidentate ligand;and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ having the meaningsmentioned before.

In another most preferred embodiment, the metal carbene complexaccording to the present invention has the formula (B), preferably theformula (II) mentioned above

wherein

is NR^(x), O or S, preferably NR^(x) or O, more preferably NR^(x);

R^(x) is

M is Ir;m is 3; o is 0, wherein the m carbene ligands may be the same ordifferent, preferably the same; andL is a monoanionic bidentate ligand;and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ having the meaningsmentioned before.

Preferably, L in the metal carbene complex according to the presentinvention is a group of formula

preferably

whereinR¹⁰, R¹², R¹³, R¹⁶, R¹⁷, R¹⁸ and R¹⁹the radicals R¹⁰, R¹², R¹³, R¹⁶, R¹⁷, R¹⁸ and R¹⁹ are—in eachcase—independently of each other a C₁-C₁₈alkyl group, which canoptionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one heteroatom selected from —O—, —S— and —NR⁶⁵—, optionallybearing at least one substituent E; a halogen atom, especially F or Cl;C₁-C₈haloalkyl such as CF₃; CN; or SiR⁸⁰R⁸¹R⁸²; orone radical R¹⁰ and/or one radical R¹²; one radical R¹³ and/or oneradical R¹²; one radical R¹⁶ and/or one radical R¹⁷; one radical R¹⁸and/or one radical R¹⁹ is a group of formula

R^(a) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group, preferably C₁-C₅-alkyl, or H, more preferably H,R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group, preferably C₁-C₅-alkyl, or H, more preferably H,R^(c), R^(b) and R^(d) are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by G; a C₃-C₁₀heterocycloalkyl radical which is interruptedby at least one of O, S and NR⁶⁵ and/or substituted by E; a C₆-C₂₄arylgroup, which can optionally be substituted by G; or a C₂-C₃₀heteroarylgroup, which can optionally be substituted by G; a halogen atom,especially F or Cl; C₁-C₈haloalkyl such as CF₃; CN; or SiR⁸⁰R⁸¹R⁸²;preferably H or a C₁-C₈alkyl group, more preferably, R^(d) is H and oneof R^(b) or R^(c) is a C₁-C₈alkyl group and the other one of R^(b) andR^(d) is H; even more preferably R^(c), R^(b) and R^(d) are H;ortwo adjacent radicals R¹⁰ and/or two adjacent radicals R¹²; two adjacentradicals R¹³ and/or two adjacent radicals R¹²; two adjacent radicals R¹⁶and/or two adjacent radicals R¹⁷; or two adjacent radicals R¹⁹; or R^(c)and R^(b), or R^(a) and R^(b) together form a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O; R′″ is C₁-C₈alkyl anda′ is 0 or 1, preferably 0;preferably, the radicals R¹⁰, R¹², R¹³, R¹⁶, R¹⁷, R¹⁸ and R¹⁹ are—ineach case—independently of each other a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D, especially methyl, ethyl, i-propyl, n-butyl,sec-butyl, tert-butyl or isoamyl; a C₃-C₆cycloalkyl group, which canoptionally be substituted by at least one substituent E; F;Cl; C₁-C₈haloalkyl such as CF₃; CN;in a further preferred embodiment, R¹⁰, R¹², R¹³, R¹⁶, R¹⁷, R¹⁸ and R19are—in each case—independently of each other hydrogen, a C₁-C₈alkylgroup especially methyl, ethyl, i-propyl, n-butyl, sec-butyl, tert-butylor isoamyl; or a phenyl group, which can optionally be substituted byone or two groups G; or a C₂-C₃₀heteroaryl group, which can optionallybe substituted by G; more preferably hydrogen, a C₁-C₈alkyl groupespecially methyl, ethyl, i-propyl, n-butyl, sec-butyl, tert-butyl orisoamyl; or a phenyl group, which can optionally be substituted by oneor two C₁-C₈alkyl groups, for example 2-tolyl, 3-tolyl, 4-tolyl,2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-isopropylphenyl,3-isopropylphenyl or 4-isopropylphenyl; most preferably hydrogen or aC₁-C₈alkyl group especially methyl, ethyl, i-propyl, n-butyl, sec-butyl,tert-butyl or isoamyl.ortwo adjacent radicals R¹⁰ and/or two adjacent radicals R¹²; two adjacentradicals R¹³ and/or two adjacent radicals R¹²; two adjacent radicals R¹⁶and/or two adjacent radicals R¹⁷; or two adjacent radicals R¹⁹ togetherform a group of formula

wherein Z is N or CR′″, wherein 0 or 1 Z is N, preferably

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴, preferably O or S; more preferablyO; R′″ is C₁-C₈alkyl and a′ is 0 or 1, preferably 0;R¹¹, R¹⁴, R²⁰, R²¹, R²², R²³ and R²⁴:the radicals R¹¹, R¹⁴, R²⁰, R²¹, R²², R²³ and R²⁴ are—in eachcase—independently of each other a C₁-C₁₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one heteroatomselected from —O—, —S— and —NR⁶⁵—, optionally bearing at least onesubstituent E; a C₆-C₁₄aryl group, which can optionally be substitutedby one or two groups G; a heteroaryl group comprising 3 to 11 ringatoms, which can optionally be substituted by one or two groups G; or a—NR⁶⁵-phenyl group, which can optionally be substituted by one or twogroups G;preferably, R¹¹, R¹⁴, R²⁰, R²¹, R²², R²³ and R²⁴ are—in eachcase—independently of each other hydrogen; a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent E; or a phenyl group, which canoptionally be substituted by one or two groups G; C₁-C₈ haloalkyl suchas CF₃; or SiR⁸⁰R⁸¹R⁸²; or in the case of X-1, X-2, X-3, X-31, X-34,X-35, X-36, X-37 and X-38 CN;ortwo adjacent radicals R¹¹ or two adjacent radicals R¹⁴ form together agroup

wherein A²¹, A^(21′), A²², A^(22′), A²³, A^(23′), A^(24′) and A²⁴ areindependently of each other H, a C₁-C₄alkyl group, a C₃-C₆cycloalkylgroup, or a fluoroC₁-C₄alkyl group;preferably, R¹¹, R¹⁴, R²⁰, R²¹, R²², R²³ and R²⁴ are—in eachcase—independently of each other a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D, especially methyl, ethyl, i-propyl, n-butyl,sec-butyl, tert-butyl or isoamyl; a C₃-C₆cycloalkyl group, which canoptionally be substituted by at least one substituent E; C₁-C₈haloalkylsuch as CF₃; or in the case of X-1, X-2, X-3, X-31, X-34, X-35, X-36,X-37 and X-38 CN;in a further preferred embodiment R¹¹, R¹⁴, R²⁰, R²¹, R²², R²³ and R²⁴are—in each case—independently of each other hydrogen, a C₁-C₈alkylgroup especially methyl, ethyl, i-propyl, n-butyl, sec-butyl, tert-butylor isoamyl; or a phenyl group, which can optionally be substituted byone or two groups G; or a C₂-C₃₀heteroaryl group, which can optionallybe substituted by G; more preferably hydrogen, a C₁-C₈alkyl groupespecially methyl, ethyl, i-propyl, n-butyl, sec-butyl, tert-butyl orisoamyl; or a phenyl group, which can optionally be substituted by oneor two C₁-C₈alkyl groups, for example 2-tolyl, 3-tolyl, 4-tolyl,2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-isopropylphenyl,3-isopropylphenyl or 4-isopropylphenyl; most preferably hydrogen or aC₁-C₈alkyl group especially methyl, ethyl, i-propyl, n-butyl, sec-butyl,tert-butyl or isoamyl;ortwo adjacent radicals R¹¹ or two adjacent radicals R¹⁴ form together agroup

wherein A²¹, A^(21′), A²², A^(22′), A²³, A^(23′), A^(24′) and A²⁴ areindependently of each other H, a C₁-C₄alkyl group, a C₃-C₆cycloalkylgroup, or a fluoroC₁-C₄alkyl group;R²⁵ is CH₃ or ethyl or iso-propyl;R²⁶ is a phenyl group, which can optionally be substituted by one or twogroups selected from CF₃ and C₁-C₈alkyl; preferably optionallysubstituted by one or two C₁-C₈alkyl groups; or R²⁶ is CH₃; oriso-propyl; preferably, R²⁶ is a phenyl group, which can optionally besubstituted by one or two groups selected from CF₃ and C₁-C₈alkylpreferably optionally substituted by one or two C₁-C₈alkyl groups; in afurther preferred embodiment R²⁶ is a phenyl group, which is substitutedby one or two phenyl groups;D is —S—, —O—, or —NR⁶⁵—;E is —OR⁶⁹, —CN, CF₃, C₁-C₈alkyl or F; preferably CF₃ or C₁-C₈alkyl;more preferably C₁-C₈alkyl;G is —OR⁶⁹, —CN, CF₃ or C₁-C₈alkyl; preferably C₁-C₈alkyl;R⁶⁵ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; and R⁶⁹ is a phenyl group, which canoptionally be substituted by one or two C₁-C₈alkyl groups; anunsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—; A¹ is C₆-C₁₀aryl;ortwo adjoint groups A¹ together form a group

wherein R^(f), R^(g), R^(h) and R^(i) are independently of each other H,or C₁-C₈alkyl;Q¹ and Q² are independently of each other hydrogen, C₁-C₁₈alkyl, orC₆-C₁₈aryl;w, x are are independently of each other 0, 1 or 2, preferably 0 or 1;more preferably 0;z is 0, 1, 2 or 3, preferably 0, 1, more preferably 0;y, y′, y″, u, v

-   -   are independently of each other 0, 1 or 2, preferably 0 or 2;        more preferably 0;        y″′ is 0 or 1, preferably 0;        p, q, r, s, t, t′, t″    -   are are independently of each other 0, 1, 2, 3 or 4, preferably        0, 1, 2 or 3;        r′ is 0, 1 or 2, preferably 0 or 1, more preferably 0.

Preferably, L in the metal carbene complex according to the presentinvention is a group of formula (X-1), (X-2), (X-3), (X-4), (X-5),preferably (X-5a) and (X-5b), (X-8), (X-9), (X-10), (X-11), (X-12),(X-13), (X-14), (X-15), (X-16), (X-17), (X-18), (X-20), (X-21), (X-22),(X-23), (X-24), (X-25), (X-26), (X-27), (X-28), and (X-29); or a groupof formula (X-30), (X-31), (X-32), (X-33), (X-34), (X-35), (X-36),(X-37), (X-38), (X-39), (X-40), (X-41), (X-42), (X-43) or (X-44).

More preferably, L in the metal carbene complex according to the presentinvention is a group of formula (X-1), (X-2), (X-3), (X-4), (X-5),preferably (X-5a) and (X-5b), (X-8), (X-9), (X-10), (X-11), (X-12),(X-13), (X-14), (X-15), (X-16), (X-17), and (X-18); or a group offormula (X-31), (X-32), (X-33), (X-34), (X-35), (X-36), (X-37), (X-38),(X-39), (X-40), (X-41), (X-42), (X-43) or (X-44).

Most preferably, L in the metal carbene complex according to the presentinvention is a group of formula (X-1), (X-2), (X-3), (X-4), (X-5),preferably (X-5a) and (X-5b), (X-8), (X-9), (X-10), (X-11), and (X-12);or a group of formula (X-31), (X-32), (X-33), (X-34), (X-35), (X-36),(X-37), (X-38), (X-39), (X-40), (X-41), (X-42), (X-43) or (X-44).

Even more preferably, L in the metal carbene complex according to thepresent invention is a group of formula (X-1), (X-4), (X-5), preferably(X-5a) and (X-5b), (X-8), (X-9), (X-10), (X-11), and (X-12); morepreferably (X-1), (X-4), (X-5), (X-8), (X-9), and (X-12).

Most preferably, L in the metal carbene complex according to the presentinvention is a group of formula (X-1) or (X-4).

In a further preferred embodiment, L in the metal carbene complexaccording to the present invention is a group of formula (X-1), (X-2),(X-3), (X-4), (X-5a), (X-8, wherein R²⁶ is a phenyl group, which canoptionally be substituted by one or two groups selected from CF₃ andC₁-C₈alkyl), (X-31), (X-34), (X-36), (X-38), (X-40), (X-42) or (X-44).

In a further more preferred embodiment, L in the metal carbene complexaccording to the present invention is a group of formula (X-1), (X-2),(X-3), (X-4), (X-5a), (X-8, wherein R²⁶ is a phenyl group, which canoptionally be substituted by one or two selected from CF₃ andC₁-C₈alkyl), (X-31), (X-34) or (X-44).

In a further even more preferred embodiment, L in the metal carbenecomplex according to the present invention is a group of formula (X-1),(X-4), (X-5a), (X-8, wherein R²⁶ is a phenyl group, which can optionallybe substituted by one or two selected from CF₃ and C₁-C₈alkyl) or(X-31); further even more preferably L is (X-1), (X-4), (X-5a) or (X-31)and most preferably, L is (X-1) or (X-4).

In a further even more preferred embodiment, L in the metal carbenecomplex according to the present invention is a group of formula (X-1),(X-5a) or (X-31), more preferably (X-1) or (X-5a).

Most preferably, L is (X-1).

The metal M in the inventive metal carbene complexes is Ir or Pt,preferably Ir, more preferably Ir (III). In the case that the metal isPt, Pt(II) is preferred.

In the most preferred metal carbene complexes of formula (II) accordingto the present invention the residues, symbols and indices have thefollowing meanings:

M is Ir;

m is 2 or 3;

o is 0 or 1; and

L is (X-1) or (X-4),

whereby the m carbene ligands are preferably the same (identical),

wherein the further residues, symbols and indices in the metal carbenecomplexes of formula (II) are the same as mentioned above.

In a further more preferred embodiment, L in the metal carbene complexmentioned above is a group of formula (X-5a), (X-31), more preferably(X-1), (X-8, wherein R²⁶ is a phenyl group, which can optionally besubstituted by one or two selected from CF₃ and C₁-C₈alkyl) or (X-31).

Even further preferred are metal carbene complexes of formula (II)according to the present invention the residues, symbols and indiceshave the following meanings:

M is Ir;

m is 2 or 3;

o is 0 or 1; and

L is (X-1) or (X-4),

whereby the m carbene ligands are preferably the same (identical);

wherein the residues R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷, R²⁸ are Hand the indices x, y, z and y″ are 0.

In a further more preferred embodiment, L in the metal carbene complexmentioned above is a group of formula (X-5a), (X-8, wherein R²⁶ is aphenyl group, which can optionally be substituted by one or two selectedfrom CF₃ and C₁-C₈alkyl) or (X-31).

In further most preferred embodiment, the residues, symbols and indicesin the metal carbene complexes of formula (II) according to the presentinvention have the following meanings:

M is Ir;

m is 1;

o is 2; and

L is (X-1), (X-4) (X-5a), (X-8, wherein R²⁶ is a phenyl group, which canoptionally be substituted by one or two selected from CF₃ andC₁-C₈alkyl) or (X-31), preferably (X-1), (X-4), (X-5a) or (X-31), evenmore preferably (X-1) or (X-4);

whereby the o carbene ligands are preferably the same (identical)

wherein the further residues, symbols and indices in the metal carbenecomplexes of formula (II) are the same as mentioned above.

In an even further preferred embodiment, the residues, symbols andindices in the metal carbene complexes of formula (II) according to thepresent invention have the following meanings:

M is Ir;

m is 1,

o is 2; and

L is (X-1), (X-4) (X-5a), (X-8, wherein R²⁶ is a phenyl group, which canoptionally be substituted by one or two selected from CF₃ andC₁-C₈alkyl) or (X-31), preferably (X-1), (X-4), (X-5a) or (X-31), evenmore preferably (X-1) or (X-4);

whereby the o carbene ligands are preferably the same (identical),

wherein the residues R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷, R²⁸ are Hand the indices x, y, z and y″ are 0.

Preferably, the metal carbene complex according to the present inventionis selected from

whereinR¹, R², R³ and R⁴are independently of each other—in each case—hydrogen; a C₁-C₈alkylgroup, which can optionally be substituted by at least one substituent Eand/or interrupted by D; a C₃-C₆cycloalkyl group, which can optionallybe substituted by at least one substituent E; or a phenyl group, whichcan optionally be substituted by one or two groups G;preferably, in the case that R¹, R², R³ and/or R⁴ are a phenyl group,which can optionally be substituted by one or two groups G; R⁵, R⁶, R⁸and R⁹ are not a phenyl group, which can optionally be substituted byone or two groups G;more preferably, R¹, R², R³ and R⁴ are independently of each other—ineach case—hydrogen; a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E;most preferably, R¹ and R⁴ as well as R² and R³ are identical; evenfurther more preferably, R¹, R², R³ and R⁴ are hydrogen;R⁵ and R⁶are independently of each other—in each case—hydrogen; a C₁-C₈alkylgroup, which can optionally be substituted by at least one substituent Eand/or interrupted by D; or a C₃-C₆cycloalkyl group, which canoptionally be substituted by at least one substituent E; or a phenylgroup, which can optionally be substituted by one or two groups G;preferably, R⁵ and R⁶ are independently of each other—in eachcase—hydrogen; a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or either R⁵ or R⁶, preferably R⁵, are a phenylgroup, which can optionally be substituted by one or two groups G;more preferably, R⁵ and R⁶ are independently of each other—in eachcase—hydrogen; a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or either R⁵ or R⁶, preferably R⁵, is a phenyl group,which can optionally be substituted by one or two groups G; in a furtherpreferred embodiment, R⁶ is a phenyl group, which can optionally besubstituted by one or two groups G; more preferably, R⁵ and R⁶ arehydrogen; R⁸ and R⁹are independently of each other hydrogen; a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; or a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent E; or a phenyl group, which canoptionally be substituted by one or two groups G;preferably, R⁸ and R⁹ are independently of each other—in eachcase—hydrogen; a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or either R⁸ or R⁹ are a phenyl group, which canoptionally be substituted by one or two groups G; more preferably, R⁸and R⁹ are independently of each other—in each case—hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; or a C₃-C₆cycloalkyl group, whichcan optionally be substituted by at least one substituent E; morepreferably, R⁹ is hydrogen and R⁸ is hydrogen or a phenyl group whichcan be optionally substituted by one or two groups G; most preferably,R⁸ and R⁹ are hydrogen;D is —S— or —O—;E is —OR⁶⁹, —CN, CF₃, C₁-C₈alkyl or F; preferably CF₃ or C₁-C₈alkyl;preferably C₁-C₈alkyl;G is —OR⁶⁹, —CN, CF₃ or C₁-C₈alkyl; preferably C₁-C₈alkyl;R⁶⁹ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkylgroup, which is interrupted by —O—;L is a monoanionic bidentate ligand, for example

as well as

preferably (X-1′), (X-4′), (X-5a′), (X-8′) or (X-31′); more preferably,(X-1′), (X-4′), (X-5a′) or (X-31′); most preferably, (X-1′), (X-4′) or(X-5a′), further most preferably, (X-1′) or (X-4′); even further mostpreferably (X-1′).m is 1, 2, or 3; preferably 2 or 3; or—in a further preferredembodiment—1;o is 0, 1, or 2; preferably 0 or 1; or—in a further preferredembodiment—2;and the sum of m+o is 3;in the case that o=2, the ligands L may be the same or different,preferably the same; and in the case that m is 2 or 3, the m carbeneligands may be the same or different, preferably the same.

More preferably, at least one of the residues R¹, R², R³, R⁴, R⁵, R⁶, R⁸and R⁹ in the complexes of formulae (IIa), (IIb), (IIc), (IId), (IIe),(IIf), (IIg) and (IIh) is not hydrogen; most preferably, in formula(IIa), two or all of R¹, R⁴, R⁶ and R⁸ are not hydrogen; in formula(IIb), two or all of R², R³, R⁶ and R⁸ are not hydrogen; in formula(IIc), two or all of R¹, R⁴, R⁵ and R⁹ are not hydrogen; in formula(IId), two or all of R², R³, R⁵ and R⁹ are not hydrogen; in formula(IIe), one or all of R¹, R⁴ and R⁵ are not hydrogen; in formula (IIf),one or all of R², R³ and R⁵ are not hydrogen; in formula (IIg), three orall of R¹, R⁴, R⁵, R⁶ and R⁸are not hydrogen; in formula (IIh), three orall of R², R³, R⁵, R⁶ and R⁸are not hydrogen.

In a further preferred embodiment, R¹, R², R³ and R⁴ are hydrogen andthe residues R⁵, R⁶ and R⁸ are as mentioned above.

In a further preferred embodiment of the present invention, R⁵, R⁶ andR⁸ in formulae (X-1′), (X-2′), (X-3′), and (X-4′) are hydrogen. In afurther preferred embodiment of the present invention, R⁵, R⁶ and R⁸ informulae (X-5a′), (X-8′) and (X-31′) are hydrogen.

More preferably, the metal carbene complex according to the presentinvention is selected from the metal carbene complexes (IIa), (IIb),(IIe), (IIf), (IIg) and (IIh). In a further more preferred embodiment,the metal carbene complex according to the present invention is selectedfrom the metal carbene complex (IId). Most preferably, the metal carbenecomplex according to the present invention is selected from the metalcarbene complexes (IIb), (IId), (IIf) and (IIh).

In a most preferred embodiment, R¹, R², R³, R⁴, R⁵, R⁶, R⁸, and R⁹ arehydrogen, i.e. the metal carbene complex of the present invention hasthe following formula:

Most preferably, the metal carbene complex according to the presentinvention is selected from

whereinR¹, R², R³ and R⁴are independently of each other—in each case—hydrogen, a C₁-C₈alkylgroup, which can optionally be substituted by at least one substituent Eand/or interrupted by D; a C₃-C₆cycloalkyl group, which can optionallybe substituted by at least one substituent E; or a phenyl group, whichcan optionally be substituted by one or two groups G;preferably, in the case that R¹, R², R³ and/or R⁴ are a phenyl group,which can optionally be substituted by one or two groups G; R⁵, R⁶, R⁸and R⁹ are not a phenyl group, which can optionally be substituted byone or two groups G;more preferably, R¹, R², R³ and R⁴ are independently of each other—ineach case—hydrogen, a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E;most preferably, R¹ and R⁴ as well as R² and R³ are identical; evenfurther more preferably, R¹, R², R³ and R⁴ are hydrogen;R⁵ and R⁶are independently of each other—in each case—hydrogen, a C₁-C₈alkylgroup, which can optionally be substituted by at least one substituent Eand/or interrupted by D; or a C₃-C₆cycloalkyl group, which canoptionally be substituted by at least one substituent E; or a phenylgroup, which can optionally be substituted by one or two groups G;preferably, R⁵ and R⁶ are independently of each other—in eachcase—hydrogen, a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or either R⁵ or R⁶, preferably R⁵, are a phenylgroup, which can optionally be substituted by one or two groups G;more preferably, R⁵ and R⁶ are independently of each other—in eachcase—hydrogen, a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or either R⁵ or R⁶, preferably R⁵, is a phenyl group,which can optionally be substituted by one or two groups G; in a furtherpreferred embodiment, R⁶ is a phenyl group, which can optionally besubstituted by one or two groups G; more preferably, R⁵ and R⁶ arehydrogen;R⁸ and R⁹are independently of each other—in each case—hydrogen, a C₁-C₈alkylgroup, which can optionally be substituted by at least one substituent Eand/or interrupted by D; or a C₃-C₆cycloalkyl group, which canoptionally be substituted by at least one substituent E; or a phenylgroup, which can optionally be substituted by one or two groups G;preferably, R⁸ and R⁹ are independently of each other—in eachcase—hydrogen, a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or either R⁸ or R⁹ are a phenyl group, which canoptionally be substituted by one or two groups G; more preferably, R⁸and R⁹ are independently of each other—in each case—a C₁-C₈alkyl group,which can optionally be substituted by at least one substituent E and/orinterrupted by D; or a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent E; more preferably, R⁹ ishydrogen and R⁸ is hydrogen or a phenyl group which can be optionallysubstituted by one or two groups G; most preferably, R⁸ and R⁹ arehydrogen;most preferably, in the case that R⁶ and R⁸ are both present, R⁶ and R⁸are identical; in the case that R⁵ and R⁹ are both present, R⁵ and R⁹are identical;D is —S— or —O—;E is —OR⁶⁹, —CN, CF₃, C₁-C₈alkyl or F; preferably CF₃ or C₁-C₈alkyl;preferably C₁-C₈alkyl;G is —OR⁶⁹, —CN, CF₃ or C₁-C₈alkyl; preferably C₁-C₈alkyl;R⁶⁹ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkylgroup, which is interrupted by —O—; m is 2 or 1, preferably 2; in thecase that m is 2, the two ligands are identical or different,preferably, the two ligands are identical;o is 1 or 2, preferably 1; in the case that m is 2, the two ligands areidentical or different, preferably, the two ligands are identical;and the sum of m+o is 3.

Preferred residues R¹, R², R³, R⁴, R⁵, R⁶, R⁸ and R⁹ and combinations ofsaid residues are mentioned above. Preferred groups D, E, G and R⁶⁹ arealso mentioned above.

In one preferred embodiment of the present invention, at least one ofthe residues R¹, R², R³, R⁴, R⁵, R⁶, R⁸ and R⁹ in each formula offormulae (II-1) to (II-74) is not hydrogen.

In a most preferred embodiment, R¹, R², R³, R⁴, R⁵, R⁶, R⁸, and R⁹ ineach formula of formulae (II-1) to (II-74) are hydrogen.

Even more preferably, the metal carbene complex according to the presentinvention is selected from the metal carbene complexes (II-1), (II-2),(II-5), (II-6), (II-7), (II-8), (II-11), (II-12), (II-13), (II-14),(II-15), (II-16), (II-17), (II-18), (II-19), (II-20), (II-21), (II-22),(II-23), (II-24), (II-25), (II-26), (II-27), (II-28), (II-29), (II-30),(II-31), (II-32), (II-33), (II-34), (II-35), (II-36), (II-37), (II-38),(II-39), (II-40), (II-41), (II-42), (II-45), and (II-46).

Additionally, even more preferably, the metal carbene complex accordingto the present invention is selected from the metal carbene complexes(II-51), (II-52), (II-53), (II-54), (II-55), (II-56), (II-57), (II-58),(II-59), (II-60), (II-61), (II-62), (II-63), (II-64), (II-65), (II-66),(II-67), (II-68), (II-69), (II-70), (II-71), (II-72), (II-73) and(II-74).

Further even more preferably, the metal carbene complex according to thepresent invention is selected from the metal carbene complexes (II-1),(II-2), (II-5), (II-6), (II-11), (II-12), (II-15), (II-16), (II-17),(II-18), (II-25), (II-26), (II-27), (II-28), (II-33), (II-34), (II-35),(II-36), (II-37), (II-38), (II-39), (II-40), (II-41), and (II-42).

Additionally, further even more preferably, the metal carbene complexaccording to the present invention is selected from the metal carbenecomplexes (II-51), (II-52), (II-53), (II-54), (II-59), (II-60), (II-63),(II-64), (II-65), (II-66), (II-71) and (II-72).

In a most preferred embodiment, R¹, R², R³, R⁴, R⁵, R⁶, R⁸, and R⁹ arehydrogen, i.e. the metal carbene complex of the present invention hasone of the following formulae:

whereinm is 1, 2 or 3, preferably 2 or 3; ando is 0, 1 or 2, preferably 0 or 1.

In a further most preferred embodiment, R¹, R², R³, R⁴, R⁵, R⁶, R⁸, andR⁹ are hydrogen, i.e. the metal carbene complex of the present inventionhas one of the formulae (II-A), (II-B), (II-C), (II-D) or (II-E) asmentioned above,

wherein

m is 1; and

o is 2.

Examples for particularly preferred metal carbene complexes according tothe present invention are mentioned in the following tables:

Cpd. R⁴ R¹ R⁶ = R⁸ A-1, A′-1, A″-1, A′′′-1, A′′′′-1, A′′′′′-1 —CH₃ —CH₃H A-2, A′-2, A″-2, A′′′-2, A′′′′-2, A′′′′′-2 —CH₂CH₃ —CH₂CH₃ H A-3,A′-3, A″-3, A′′′-3, A-′′′′-3, A′′′′′-3 n-propyl n-propyl H A-4, A′-4,A″-4, A′′′-4, A′′′′-4, A′′′′′-4 iso-propyl iso-propyl H A-5, A′-5, A″-5,A′′′-5, A′′′′-5, A′′′′′-5 sec-butyl sec-butyl H A-6, A′-6, A″-6, A′′′-6,A′′′′-6, A′′′′′-6 iso-butyl iso-butyl H A-7, A′-7, A″-7, A′′′-7,A′′′′-7, A′′′′′-7 neopentyl neopentyl H A-8, A′-8, A″-8, A′′′-8,A′′′′-8, A′′′′′-8

H A-9, A′-9, A″-9, A′′′-9, A′′′′-9, A′′′′′-9

H A-10, A′-10, A″-10, A′′′-10, A′′′′-10, A′′′′′-10 —CH₃ —CH₃ —CH₃ A-11,A′-11, A″-11, A′′′-11, A′′′′-11, A′′′′′-11 —CH₂CH₃ —CH₂CH₃ —CH₃ A-12,A′-12, A″-12, A′′′-12, A′′′′-12, A′′′′′-12 n-propyl n-propyl —CH₃ A-13,A′-13, A″-13, A′′′-13, A′′′′-13, A′′′′′-13 iso-propyl iso-propyl —CH₃A-14, A′-14, A″-14, A′′′-14, A′′′′-14, A′′′′′-14 sec-butyl sec-butyl—CH₃ A-15, A′-15, A″-15, A′′′-15, A′′′′-15, A′′′′′-15 iso-butyliso-butyl —CH₃ A-16, A′-16, A″-16, A′′′-16, A′′′′-16, A′′′′′-16neopentyl neopentyl —CH₃ A-17, A′-17, A″-17, A′′′-17, A′′′′-17,A′′′′′-17

—CH₃ A-18, A′-18, A″-18, A′′′-18, A′′′′-18, A′′′′′-18

—CH₃ A-19, A′-19, A″-19, A′′′-19, A′′′′-19, A′′′′′-19 —CH₃ —CH₃ —CH₂CH₃A-20, A′-20, A″-20, A′′′-20, A′′′′-20, A′′′′′-20 —CH₂CH₃ —CH₂CH₃ —CH₂CH₃A-21, A′-21, A″-21, A′′′-21, A′′′′-21, A′′′′′-21 n-propyl n-propyl—CH₂CH₃ A-22, A′-22, A″-22, A′′′-22, A′′′′-22, A′′′′′-22 iso-propyliso-propyl —CH₂CH₃ A-23, A′-23, A″-23, A′′′-23, A′′′′-23, A′′′′′-23sec-butyl sec-butyl —CH₂CH₃ A-24, A′-24, A″-24, A′′′-24, A′′′′-24,A′′′′′-24 iso-butyl iso-butyl —CH₂CH₃ A-25, A′-25, A″-25, A′′′-25,A′′′′-25, A′′′′′-25 neopentyl neopentyl —CH₂CH₃ A-26, A′-26, A″-26,A′′′-26, A′′′′-26, A′′′′′-26

—CH₂CH₃ A-27, A′-27, A″-27, A′′′-27, A′′′′-27, A′′′′′-27

—CH₂CH₃ A-28, A′-28, A″-28, A′′′-28, A′′′′-28, A′′′′′-28 —CH₃ —CH₃n-propyl A-29, A′-29, A″-29, A′′′-29, A′′′′-29, A′′′′′-29 —CH₂CH₃—CH₂CH₃ n-propyl A-30, A′-30, A″-30, A′′′-30, A′′′′-30, A′′′′′-30n-propyl n-propyl n-propyl A-31, A′-31, A″-31, A′′′-31, A′′′′-31,A′′′′′-31 iso-propyl iso-propyl n-propyl A-32, A′-32, A″-32, A′′′-32,A′′′′-32, A′′′′′-32 sec-butyl sec-butyl n-propyl A-33, A′-33, A″-33,A′′′-33, A′′′′-33, A′′′′′-33 iso-butyl iso-butyl n-propyl A-34, A′-34,A″-34, A′′′-34, A′′′′-34, A′′′′′-34 neopentyl neopentyl n-propyl A-35,A′-35, A″-35, A′′′-35, A′′′′-35, A′′′′′-35

n-propyl A-36, A′-36, A″-36, A′′′-36, A′′′′-36, A′′′′′-36

n-propyl A-37, A′-37, A″-37, A′′′-37, A′′′′-37, A′′′′′-37 —CH₃ —CH₃iso-propyl A-38, A′-38, A″-38, A′′′-38, A′′′′-38, A′′′′′-38 —CH₂CH₃—CH₂CH₃ iso-propyl A-39, A′-39, A″-39, A′′′-39, A′′′′-39, A′′′′′-39n-propyl n-propyl iso-propyl A-40, A′-40, A″-40, A′′′-40, A′′′′-40,A′′′′′-40 iso-propyl iso-propyl iso-propyl A-41, A′-41, A″-41, A′′′-41,A′′′′-41, A′′′′′-41 sec-butyl sec-butyl iso-propyl A-42, A′-42, A″-42,A′′′-42, A′′′′-42, A′′′′′-42 iso-butyl iso-butyl iso-propyl A-43, A′-43,A″-43, A′′′-43, A′′′′-43, A′′′′′-43 neopentyl neopentyl iso-propyl A-44,A′-44, A″-44, A′′′-44, A′′′′-44, A′′′′′-44

iso-propyl A-45, A′-45, A″-45, A′′′-45, A′′′′-45, A′′′′′-45

iso-propyl A-46, A′-46, A″-46, A′′′-46, A′′′′-46, A′′′′′-46 —CH₃ —CH₃sec-butyl A-47, A′-47, A″-47, A′′′-47, A′′′′-47, A′′′′′-47 —CH₂CH₃—CH₂CH₃ sec-butyl A-48, A′-48, A″-48, A′′′-48, A′′′′-48, A′′′′′-48n-propyl n-propyl sec-butyl A-49, A′-49, A″-49, A′′′-49, A′′′′-49,A′′′′′-49 iso-propyl iso-propyl sec-butyl A-50, A′-50, A″-50, A′′′-50,A′′′′-50, A′′′′′-50 sec-butyl sec-butyl sec-butyl A-51, A′-51, A″-51,A′′′-51, A′′′′-51, A′′′′′-51 iso-butyl iso-butyl sec-butyl A-52, A′-52,A″-52, A′′′-52, A′′′′-52, A′′′′′-52 neopentyl neopentyl sec-butyl A-53,A′-53, A″-53, A′′′-53, A′′′′-53, A′′′′′-53

sec-butyl A-54, A′-54, A″-54, A′′′-54, A′′′′-54, A′′′′′-54

sec-butyl A-55, A′-55, A″-55, A′′′-55, A′′′′-55, A′′′′′-55 —CH₃ —CH₃iso-butyl A-56, A′-56, A″-56, A′′′-56, A′′′′-56, A′′′′′-56 —CH₂CH₃—CH₂CH₃ iso-butyl A-57, A′-57, A″-57, A′′′-57, A′′′′-57, A′′′′′-57n-propyl n-propyl iso-butyl A-58, A′-58, A″-58, A′′′-58, A′′′′-58,A′′′′′-58 iso-propyl iso-propyl iso-butyl A-59, A′-59, A″-59, A′′′-59,A′′′′-59, A′′′′′-59 sec-butyl sec-butyl iso-butyl A-60, A′-60, A″-60,A′′′-60, A′′′′-60, A′′′′′-60 iso-butyl iso-butyl iso-butyl A-61, A′-61,A″-61, A′′′-61, A′′′′-61, A′′′′′-61 neopentyl neopentyl iso-butyl A-62,A′-62, A″-62, A′′′-62, A′′′′-62, A′′′′′-62

iso-butyl A-63, A′-63, A″-63, A′′′-63, A′′′′-63, A′′′′′-63

iso-butyl A-64, A′-64, A″-64, A′′′-64, A′′′′-64, A′′′′′-64 —CH₃ —CH₃neopentyl A-65, A′-65, A″-65, A′′′-65, A′′′′-65, A′′′′′-65 —CH₂CH₃—CH₂CH₃ neopentyl A-66, A′-66, A″-66, A′′′-66, A′′′′-66, A′′′′′-66n-propyl n-propyl neopentyl A-67, A′-67, A″-67, A′′′-67, A′′′′-67,A′′′′′-67 iso-propyl iso-propyl neopentyl A-68, A′-68, A″-68, A′′′-68,A′′′′-68, A′′′′′-68 sec-butyl sec-butyl neopentyl A-69, A′-69, A″-69,A′′′-69, A′′′′-69, A′′′′′-69 iso-butyl iso-butyl neopentyl A-70, A′-70,A″-70, A′′′-70, A′′′′-70, A′′′′′-70 neopentyl neopentyl neopentyl A-71,A′-71, A″-71, A′′′-71, A′′′′-71, A′′′′′-71

neopentyl A-72, A′-72, A″-72, A′′′-72, A′′′′-72, A′′′′′-72

neopentyl A-73, A′-73, A″-73, A′′′-73, A′′′′-73, A′′′′′-73 —CH₃ —CH₃

A-74, A′-74, A″-74, A′′′-74, A′′′′-74, A′′′′′-74 —CH₂CH₃ —CH₂CH₃

A-75, A′-75, A″-75, A′′′-75, A′′′′-75, A′′′′′-75 n-propyl n-propyl

A-76, A′-76, A″-76, A′′′-76, A′′′′-76, A′′′′′-76 iso-propyl iso-propyl

A-77, A′-77, A″-77, A′′′-77, A′′′′-77, A′′′′′-77 sec-butyl sec-butyl

A-78, A′-78, A″-78, A′′′-78, A′′′′-78, A′′′′′-78 iso-butyl iso-butyl

A-79, A′-79, A″-79, A′′′-79, A′′′′-79, A′′′′′-79 neopentyl neopentyl

A-80, A′-80, A″-80, A′′′-80, A′′′′-80, A′′′′′-80

A-81, A′-81, A″-81, A′′′-81, A′′′′-81, A′′′′′-81

A-82, A′-82, A″-82, A′′′-82, A′′′′-82, A′′′′′-82 —CH₃ —CH₃

A-83, A′-83, A″-83, A′′′-83, A′′′′-83, A′′′′′-83 —CH₂CH₃ —CH₂CH₃

A-84, A′-84, A″-84, A′′′-84, A′′′′-84, A′′′′′-84 n-propyl n-propyl

A-85, A′-85, A″-85, A′′′-85, A′′′′-85, A′′′′′-85 iso-propyl iso-propyl

A-86, A′-86, A″-86, A′′′-86, A′′′′-86, A′′′′′-86 sec-butyl sec-butyl

A-87, A′-87, A″-87, A′′′-87, A′′′′-87, A′′′′′-87 iso-butyl iso-butyl

A-88, A′-88, A″-88, A′′′-88, A′′′′-88, A′′′′′-88 neopentyl neopentyl

A-89, A′-89, A″-89, A′′′-89, A′′′′-89, A′′′′′-89

A-90, A′-90, A″-90, A′′′-90, A′′′′-90, A′′′′′-90

A-91, A′-91, A″-91, A′′′-91, A′′′′-91, A′′′′′-91 —CH₃ —CH₃ tert-butylA-92, A′-92, A″-92, A′′′-92, A′′′′-92, A′′′′′-92 —CH₂CH₃ —CH₂CH₃tert-butyl A-93, A′-93, A″-93, A′′′-93, A′′′′-93, A′′′′′-93 n-propyln-propyl tert-butyl A-94, A′-94, A″-94, A′′′-94, A′′′′-94, A′′′′′-94iso-propyl iso-propyl tert-butyl A-95, A′-95, A″-95, A′′′-95, A′′′′-95,A′′′′′-95 sec-butyl sec-butyl tert-butyl A-96, A′-96, A″-96, A′′′-96,A′′′′-96, A′′′′′-96 iso-butyl iso-butyl tert-butyl A-97, A′-97, A″-97,A′′′-97, A′′′′-97, A′′′′′-97 neopentyl neopentyl tert-butyl A-98, A′-98,A″-98, A′′′-98, A′′′′-98, A′′′′′-98

tert-butyl A-99, A′-99, A″-99, A′′′-99, A′′′′-99, A′′′′′-99

tert-butyl A-100, A′-100, A″-100, A′′′-100, A′′′′-100, —CH₃ —CH₃tert-amyl A′′′′′-100 A-101, A′-101, A″-101, A′′′-101, A′′′′-101, —CH₂CH₃—CH₂CH₃ tert-amyl A′′′′′-101 A-102, A′-102, A″-102, A′′′-102, A′′′′-102,n-propyl n-propyl tert-amyl A′′′′′-102 A-103, A′-103, A″-103, A′′′-103,A′′′′-103, iso-propyl iso-propyl tert-amyl A′′′′′-103 A-104, A′-104,A″-104, A′′′-104, A′′′′-104, sec-butyl sec-butyl tert-amyl A′′′′′-104A-105, A′-105, A″-105, A′′′-105, A′′′′-105, iso-butyl iso-butyltert-amyl A′′′′′-105 A-106, A′-106, A″-106, A′′′-106, A′′′′-106,neopentyl neopentyl tert-amyl A′′′′′-106 A-107, A′-107, A″-107,A′′′-107, A′′′′-107, A′′′′′-107

tert-amyl A-108, A′-108, A″-108, A′′′-108, A′′′′-108, A′′′′′-108

tert-amyl A-109, A′-109, A″-109, A′′′-109, A′′′′-109, tert-butyltert-butyl —CH₃ A′′′′′-109 A-110, A″-110, A″-110, A′′′-110, A′′′′-110,tert-butyl tert-butyl —CH₂CH₃ A′′′′′-110 A-111, A′-111, A″-111,A′′′-111, A′′′′-111, ten-butyl tert-butyl n-propyl A′′′′′-111 A-112,A′-112, A″-112, A′′′-112, A′′′′-112, tert-butyl tert-butyl iso-propylA′′′′′-112 A-113, A′-113, A″-113, A′′′-113, A′′′′-113, tert-butyltert-butyl sec-butyl A′′′′′-113 A-114, A′-114, A″-114, A′′′-114,A′′′′-114, tert-butyl tert-butyl iso-butyl A′′′′′-114 A-115, A′-115,A″-115, A′′′-115, A′′′′-115, tert-butyl tert-butyl neopentyl A′′′′′-115A-116, A′-116, A″-116, A′′′-116, A′′′′-116, A′′′′′-116 tert-butyltert-butyl

A-117, A′-117, A″-117, A′′′-117, A′′′′-117, A′′′′′-117 tert-butyltert-butyl

A-118, A′-118, A″-118, A′′′-118, A′′′′-118, tert-butyl tert-butyltert-butyl A′′′′′-118 A-119, A′-119, A″-119, A′′′-119, A′′′′-119,tert-butyl tert-butyl tert-amyl A′′′′′-119 A-120, A′-120, A″-120,A′′′-120, A′′′′-120, tert-amyl tert-amyl —CH₃ A′′′′′-120 A-121, A′-121,A″-121, A′′′-121, A′′′′-121, tert-amyl tert-amyl —CH₂CH₃ A′′′′′-121A-122, A′-122, A″-122, A′′′-122, A′′′′-122, tert-amyl tert-amyl n-propylA′′′′′-122 A-123, A′-123, A″-123, A′′′-123, A′′′′-123, tert-amyltert-amyl iso-propyl A′′′′′-123 A-124, A′-124, A″-124, A′′′-124,A′′′′-124, tert-amyl tert-amyl sec-butyl A′′′′′-124 A-125, A′-125,A″-125, A′′′-125, A′′′′-125, tert-amyl tert-amyl iso-butyl A′′′′′-125A-126, A′-126, A″-126, A′′′-126, A′′′′-126, tert-amyl tert-amylneopentyl A′′′′′-126 A-127, A′-127, A″-127, A′′′-127, A′′′′-127,A′′′′′-127 tert-amyl tert-amyl

A-128, A′-128, A″-128, A′′′-128, A′′′′-128, A′′′′′-128 tert-amyltert-amyl

A-129, A′-129, A″-129, A′′′-129, A′′′′-129, tert-amyl tert-amyltert-butyl A′′′′′-129 A-130, A′-130, A″-130, A′′′-130, A′′′′-130,tert-amyl tert-amyl tert-amyl A′′′′′-130 A-131, A′-131, A″-131,A′′′-131, A′′′′-131, tert-butyl tert-butyl H A′′′′′-131 A-132, A′-132,A″-132, A′′′-132, A′′′′-132, tert-amyl tert-amyl H A′′′′′-132 A-133,A′-133, A″-133, A′′′-133, A′′′′-133, H H H A′′′′′-133

Preferred compounds A, A′, A″, A″′, A″″ and A′″″ are compounds A-1,A′-1, A″-1, A″′-1, A″″ and A′″″-1 to A-90, A′-90, A″-90, A″′-90, A″″-90and A′″″-90. Further most preferred compounds are A-133, A′-133, A″-133,A″″-133, A″″-133 and A′″″-133.

Cpd. R³ R² R⁶ = R⁸ B-1, B′-1, B′′-1, B′′′-1, B′′′′-1, B′′′′′-1 —CH₃ —CH₃H B-2, B′-2, B′′-2, B′′′-2, B′′′′-2, B′′′′′-2 —CH₂CH₃ —CH₂CH₃ H B-3,B′-3, B′′-3, B′′′-3, B′′′′-3, B′′′′′-3 n-propyl n-propyl H B-4, B′-4,B′′-4, B′′′-4, B′′′′-4, B′′′′′-4 iso-propyl iso-propyl H B-5, B′-5,B′′-5, B′′′-5, B′′′′-5, B′′′′′-5 sec-butyl sec-butyl H B-6, B′-6, B′′-6,B′′′-6, B′′′′-6, B′′′′′-6 iso-butyl iso-butyl H B-7, B′-7, B′′-7,B′′′-7, B′′′′-7, B′′′′′-7 neopentyl neopentyl H B-8, B′-8, B′′-8,B′′′-8, B′′′′-8, B′′′′′-8

H B-9, B′-9, B′′-9, B′′′-9, B′′′′-9, B′′′′′-9

H B-10, B′-10, B′′-10, B′′′-10, B′′′′-10, B′′′′′-10 —CH₃ —CH₃ —CH₃ B-11,B′-11, B′′-11, B′′′-11, B′′′′-11, B′′′′′-11 —CH₂CH₃ —CH₂CH₃ —CH₃ B-12,B′-12, B′′-12, B′′′-12, B′′′′-12, B′′′′′-12 n-propyl n-propyl —CH₃ B-13,B′-13, B′′-13, B′′′-13, B′′′′-13, B′′′′′-13 iso-propyl iso-propyl —CH₃B-14, B′-14, B′′-14, B′′′-14, B′′′′-14, B′′′′′-14 sec-butyl sec-butyl—CH₃ B-15, B′-15, B′′-15, B′′′-15, B′′′′-15, B′′′′′-15 iso-butyliso-butyl —CH₃ B-16, B′-16, B′′-16, B′′′-16, B′′′′-16, B′′′′′-16neopentyl neopentyl —CH₃ B-17, B′-17, B′′-17, B′′′-17, B′′′′-17,B′′′′′-17

—CH₃ B-18, B′-18, B′′-18, B′′′-18, B′′′′-18, B′′′′′-18

—CH₃ B-19, B′-19, B′′-19, B′′′-19, B′′′′-19, B′′′′′-19 —CH₃ —CH₃ —CH₂CH₃B-20, B′-20, B′′-20, B′′′-20, B′′′′-20, B′′′′′-20 —CH₂CH₃ —CH₂CH₃—CH₂CH₃ B-21, B′-21, B′′-21, B′′′-21, B′′′′-21, B′′′′′-21 n-propyln-propyl —CH₂CH₃ B-22, B′-22, B′′-22, B′′′-22, B′′′′-22, B′′′′′-22iso-propyl iso-propyl —CH₂CH₃ B-23, B′-23, B′′-23, B′′′-23, B′′′′-23,B′′′′′-23 sec-butyl sec-butyl —CH₂CH₃ B-24, B′-24, B′′-24, B′′′-24,B′′′′-24, B′′′′′-24 iso-butyl iso-butyl —CH₂CH₃ B-25, B′-25, B′′-25,B′′′-25, B′′′′-25, B′′′′′-25 neopentyl neopentyl —CH₂CH₃ B-26, B′-26,B′′-26, B′′′-26, B′′′′-26, B′′′′′-26

—CH₂CH₃ B-27, B′-27, B′′-27, B′′′-27, B′′′′-27, B′′′′′-27

—CH₂CH₃ B-28, B′-28, B′′-28, B′′′-28, B′′′′-28, B′′′′′-28 —CH₃ —CH₃n-propyl B-29, B′-29, B′′-29, B′′′-29, B′′′′-29, B′′′′′-29 —CH₂CH₃—CH₂CH₃ n-propyl B-30, B′-30, B′′-30, B′′′-30, B′′′′-30, B′′′′′-30n-propyl n-propyl n-propyl B-31, B′-31, B′′-31, B′′′-31, B′′′′-31,B′′′′′-31 iso-propyl iso-propyl n-propyl B-32, B′-32, B′′-32, B′′′-32,B′′′′-32, B′′′′′-32 sec-butyl sec-butyl n-propyl B-33, B′-33, B′′-33,B′′′-33, B′′′′-33, B′′′′′-33 iso-butyl iso-butyl n-propyl B-34, B′-34,B′′-34, B′′′-34, B′′′′-34, B′′′′′-34 neopentyl neopentyl n-propyl B-35,B′-35, B′′-35, B′′′-35, B′′′′-35, B′′′′′-35

n-propyl B-36, B′-36, B′′-36, B′′′-36, B′′′′-36, B′′′′′-36

n-propyl B-37, B′-37, B′′-37, B′′′-37, B′′′′-37, B′′′′′-37 —CH₃ —CH₃iso-propyl B-38, B′-38, B′′-38, B′′′-38, B′′′′-38, B′′′′′-38 —CH₂CH₃—CH₂CH₃ iso-propyl B-39, B′-39, B′′-39, B′′′-39, B′′′′-39, B′′′′′-39n-propyl n-propyl iso-propyl B-40, B′-40, B′′-40, B′′′-40, B′′′′-40,B′′′′′-40 iso-propyl iso-propyl iso-propyl B-41, B′-41, B′′-41, B′′′-41,B′′′′-41, B′′′′′-41 sec-butyl sec-butyl iso-propyl B-42, B′-42, B′′-42,B′′′-42, B′′′′-42, B′′′′′-42 iso-butyl iso-butyl iso-propyl B-43, B′-43,B′′-43, B′′′-43, B′′′′-43, B′′′′′-43 neopentyl neopentyl iso-propylB-44, B′-44, B′′-44, B′′′-44, B′′′′-44, B′′′′′-44

iso-propyl B-45, B′-45, B′′-45, B′′′-45, B′′′′-45, B′′′′′-45

iso-propyl B-46, B′-46, B′′-46, B′′′-46, B′′′′-46, B′′′′′-46 —CH₃ —CH₃sec-butyl B-47, B′-47, B′′-47, B′′′-47, B′′′′-47, B′′′′′-47 —CH₂CH₃—CH₂CH₃ sec-butyl B-48, B′-48, B′′-48, B′′′-48, B′′′′-48, B′′′′′-48n-propyl n-propyl sec-butyl B-49, B′-49, B′′-49, B′′′-49, B′′′′-49,B′′′′′-49 iso-propyl iso-propyl sec-butyl B-50, B′-50, B′′-50, B′′′-50,B′′′′-50, B′′′′′-50 sec-butyl sec-butyl sec-butyl B-51, B′-51, B′′-51,B′′′-51, B′′′′-51, B′′′′′-51 iso-butyl iso-butyl sec-butyl B-52, B′-52,B′′-52, B′′′-52, B′′′′-52, B′′′′′-52 neopentyl neopentyl sec-butyl B-53,B′-53, B′′-53, B′′′-53, B′′′′-53, B′′′′′-53

sec-butyl B-54, B′-54, B′′-54, B′′′-54, B′′′′-54, B′′′′′-54

sec-butyl B-55, B′-55, B′′-55, B′′′-55, B′′′′-55, B′′′′′-55 —CH₃ —CH₃iso-butyl B-56, B′-56, B′′-56, B′′′-56, B′′′′-56, B′′′′′-56 —CH₂CH₃—CH₂CH₃ iso-butyl B-57, B′-57, B′′-57, B′′′-57, B′′′′-57, B′′′′′-57n-propyl n-propyl iso-butyl B-58, B′-58, B′′-58, B′′′-58, B′′′′-58,B′′′′′-58 iso-propyl iso-propyl iso-butyl B-59, B′-59, B′′-59, B′′′-59,B′′′′-59, B′′′′′-59 sec-butyl sec-butyl iso-butyl B-60, B′-60, B′′-60,B′′′-60, B′′′′-60, B′′′′′-60 iso-butyl iso-butyl iso-butyl B-61, B′-61,B′′-61, B′′′-61, B′′′′-61, B′′′′′-61 neopentyl neopentyl iso-butyl B-62,B′-62, B′′-62, B′′′-62, B′′′′-62, B′′′′′-62

iso-butyl B-63, B′-63, B′′-63, B′′′-63, B′′′′-63, B′′′′′-63

iso-butyl B-64, B′-64, B′′-64, B′′′-64, B′′′′-64, B′′′′′-64 —CH₃ —CH₃neopentyl B-65, B′-65, B′′-65, B′′′-65, B′′′′-65, B′′′′′-65 —CH₂CH₃—CH₂CH₃ neopentyl B-66, B′-66, B′′-66, B′′′-66, B′′′′-66, B′′′′′-66n-propyl n-propyl neopentyl B-67, B′-67, B′′-67, B′′′-67, B′′′′-67,B′′′′′-67 iso-propyl iso-propyl neopentyl B-68, B′-68, B′′-68, B′′′-68,B′′′′-68, B′′′′′-68 sec-butyl sec-butyl neopentyl B-69, B′-69, B′′-69,B′′′-69, B′′′′-69, B′′′′′-69 iso-butyl iso-butyl neopentyl B-70, B′-70,B′′-70, B′′′-70, B′′′′-70, B′′′′′-70 neopentyl neopentyl neopentyl B-71,B′-71, B′′-71, B′′′-71, B′′′′-71, B′′′′′-71

neopentyl B-72, B′-72, B′′-72, B′′′-72, B′′′′-72, B′′′′′-72

neopentyl B-73, B′-73, B′′-73, B′′′-73, B′′′′-73, B′′′′′-73 —CH₃ —CH₃

B-74, B′-74, B′′-74, B′′′-74, B′′′′-74, B′′′′′-74 —CH₂CH₃ —CH₂CH₃

B-75, B′-75, B′′-75, B′′′-75, B′′′′-75, B′′′′′-75 n-propyl n-propyl

B-76, B′-76, B′′-76, B′′′-76, B′′′′-76, B′′′′′-76 iso-propyl iso-propyl

B-77, B′-77, B′′-77, B′′′-77, B′′′′-77, B′′′′′-77 sec-butyl sec-butyl

B-78, B′-78, B′′-78, B′′′-78, B′′′′-78, B′′′′′-78 iso-butyl iso-butyl

B-79, B′-79, B′′-79, B′′′-79, B′′′′-79, B′′′′′-79 neopentyl neopentyl

B-80, B′-80, B′′-80, B′′′-80, B′′′′-80, B′′′′′-80

B-81, B′-81, B′′-81, B′′′-81, B′′′′-81, B′′′′′-81

B-82, B′-82, B′′-82, B′′′-82, B′′′′-82, B′′′′′-82 —CH₃ —CH₃

B-83, B′-83, B′′-83, B′′′-83, B′′′′-83, B′′′′′-83 —CH₂CH₃ —CH₂CH₃

B-84, B′-84, B′′-84, B′′′-84, B′′′′-84, B′′′′′-84 n-propyl n-propyl

B-85, B′-85, B′′-85, B′′′-85, B′′′′-85, B′′′′′-85 iso-propyl iso-propyl

B-86, B′-86, B′′-86, B′′′-86, B′′′′-86, B′′′′′-86 sec-butyl sec-butyl

B-87, B′-87, B′′-87, B′′′-87, B′′′′-87, B′′′′′-87 iso-butyl iso-butyl

B-88, B′-88, B′′-88, B′′′-88, B′′′′-88, B′′′′′-88 neopentyl neopentyl

B-89, B′-89, B′′-89, B′′′-89, B′′′′-89, B′′′′′-89

B-90, B′-90, B′′-90, B′′′-90, B′′′′-90, B′′′′′-90

B-91, B′-91, B′′-91, B′′′-91, B′′′′-91, B′′′′′-91 —CH₃ —CH₃ tert-butylB-92, B′-92, B′′-92, B′′′-92, B′′′′-92, B′′′′′-92 —CH₂CH₃ —CH₂CH₃tert-butyl B-93, B′-93, B′′-93, B′′′-93, B′′′′-93, B′′′′′-93 n-propyln-propyl tert-butyl B-94, B′-94, B′′-94, B′′′-94, B′′′′-94, B′′′′′-94iso-propyl iso-propyl tert-butyl B-95, B′-95, B′′-95, B′′′-95, B′′′′-95,B′′′′′-95 sec-butyl sec-butyl tert-butyl B-96, B′-96, B′′-96, B′′′-96,B′′′′-96, B′′′′′-96 iso-butyl iso-butyl tert-butyl B-97, B′-97, B′′-97,B′′′-97, B′′′′-97, B′′′′′-97 neopentyl neopentyl tert-butyl B-98, B′-98,B′′-98, B′′′-98, B′′′′-98, B′′′′′-98

tert-butyl B-99, B′-99, B′′-99, B′′′-99, B′′′′-99, B′′′′′-99

tert-butyl B-100, B′-100, B′′-100, B′′′-100, B′′′′-100, B′′′′′-100 —CH₃—CH₃ tert-amyl B-101, B′-100, B′′-101, B′′′-101, B′′′′-101, B′′′′′-101—CH₂CH₃ —CH₂CH₃ tert-amyl B-102, B′-100, B′′-102, B′′′-102, B′′′′-102,B′′′′′-102 n-propyl n-propyl tert-amyl B-103, B′-100, B′′-103, B′′′-103,B′′′′-103, B′′′′′-103 iso-propyl iso-propyl tert-amyl B-104, B′-100,B′′-104, B′′′-104, B′′′′-104, B′′′′′-104 sec-butyl sec-butyl tert-amylB-105, B′-100, B′′-105, B′′′-105, B′′′′-105, B′′′′′-105 iso-butyliso-butyl tert-amyl B-106, B′-100, B′′-106, B′′′-106, B′′′′-106,B′′′′′-106 neopentyl neopentyl tert-amyl B-107, B′-100, B′′-107,B′′′-107, B′′′′-107, B′′′′′-107

tert-amyl B-108, B′-100, B′′-108, B′′′-108, B′′′′-108, B′′′′′-108

tert-amyl

Preferred compounds B, B′, B″, B″′, B″″ and B′″″ are compounds B-1,B′-1, B″-1, B″′-1, B″″-1 and B′″″-1 to B-90, B′-90, B″-90, B″′-90,B″″-90 and B″″′-90.

Cpd. R⁴ R¹ R⁵ = R⁶ = R⁸ C-1 —CH₃ —CH₃ H C-2 —CH₂CH₃ —CH₂CH₃ H C-3n-propyl n-propyl H C-4 iso-propyl iso-propyl H C-5 sec-butyl sec-butylH C-6 iso-butyl iso-butyl H C-7 neopentyl Neopentyl H C-8

H C-9

H C-10 —CH₃ —CH₃ —CH₃ C-11 —CH₂CH₃ —CH₂CH₃ —CH₃ C-12 n-propyl n-propyl—CH₃ C-13 iso-propyl iso-propyl —CH₃ C-14 sec-butyl sec-butyl —CH₃ C-15iso-butyl iso-butyl —CH₃ C-16 neopentyl Neopentyl —CH₃ C-17

—CH₃ C-18

—CH₃ C-19 —CH₃ —CH₃ —CH₂CH₃ C-20 —CH₂CH₃ —CH₂CH₃ —CH₂CH₃ C-21 n-propyln-propyl —CH₂CH₃ C-22 iso-propyl iso-propyl —CH₂CH₃ C-23 sec-butylsec-butyl —CH₂CH₃ C-24 iso-butyl iso-butyl —CH₂CH₃ C-25 neopentylNeopentyl —CH₂CH₃ C-26

—CH₂CH₃ C-27

—CH₂CH₃ C-28 —CH₃ —CH₃ n-propyl C-29 —CH₂CH₃ —CH₂CH₃ n-propyl C-30n-propyl n-propyl n-propyl C-31 iso-propyl iso-propyl n-propyl C-32sec-butyl sec-butyl n-propyl C-33 iso-butyl iso-butyl n-propyl C-34neopentyl Neopentyl n-propyl C-35

n-propyl C-36

n-propyl C-37 —CH₃ —CH₃ iso-propyl C-38 —CH₂CH₃ —CH₂CH₃ iso-propyl C-39n-propyl n-propyl iso-propyl C-40 iso-propyl iso-propyl iso-propyl C-41sec-butyl sec-butyl iso-propyl C-42 iso-butyl iso-butyl iso-propyl C-43neopentyl Neopentyl iso-propyl C-44

iso-propyl C-45

iso-propyl C-46 —CH₃ —CH₃ sec-butyl C-47 —CH₂CH₃ —CH₂CH₃ sec-butyl C-48n-propyl n-propyl sec-butyl C-49 iso-propyl iso-propyl sec-butyl C-50sec-butyl sec-butyl sec-butyl C-51 iso-butyl iso-butyl sec-butyl C-52neopentyl Neopentyl sec-butyl C-53

sec-butyl C-54

sec-butyl C-55 —CH₃ —CH₃ iso-butyl C-56 —CH₂CH₃ —CH₂CH₃ iso-butyl C-57n-propyl n-propyl iso-butyl C-58 iso-propyl iso-propyl iso-butyl C-59sec-butyl sec-butyl iso-butyl C-60 iso-butyl iso-butyl iso-butyl C-61neopentyl Neopentyl iso-butyl C-62

iso-butyl C-63

iso-butyl C-64 —CH₃ —CH₃ neopentyl C-65 —CH₂CH₃ —CH₂CH₃ neopentyl C-66n-propyl n-propyl neopentyl C-67 iso-propyl iso-propyl neopentyl C-68sec-butyl sec-butyl neopentyl C-69 iso-butyl iso-butyl neopentyl C-70neopentyl Neopentyl neopentyl C-71

neopentyl C-72

neopentyl C-73 —CH₃ —CH₃

C-74 —CH₂CH₃ —CH₂CH₃

C-75 n-propyl n-propyl

C-76 iso-propyl iso-propyl

C-77 sec-butyl sec-butyl

C-78 iso-butyl iso-butyl

C-79 neopentyl Neopentyl

C-80

C-81

C-82 —CH₃ —CH₃

C-83 —CH₂CH₃ —CH₂CH₃

C-84 n-propyl n-propyl

C-85 iso-propyl iso-propyl

C-86 sec-butyl sec-butyl

C-87 iso-butyl iso-butyl

C-88 neopentyl Neopentyl

C-89

C-90

C-91 tert-butyl tert-butyl —CH₃ C-92 tert-butyl tert-butyl —CH₂CH₃ C-93tert-butyl tert-butyl n-propyl C-94 tert-butyl tert-butyl iso-propylC-95 tert-butyl tert-butyl sec-butyl C-96 tert-butyl tert-butyliso-butyl C-97 tert-butyl tert-butyl neopentyl C-98 tert-butyltert-butyl

C-99 tert-butyl tert-butyl

C-100 tert-amyl tert-amyl —CH₃ C-101 tert-amyl tert-amyl —CH₂CH₃ C-102tert-amyl tert-amyl n-propyl C-103 tert-amyl tert-amyl iso-propyl C-104tert-amyl tert-amyl sec-butyl C-105 tert-amyl tert-amyl iso-butyl C-106tert-amyl tert-amyl neopentyl C-107 tert-amyl tert-amyl

C-108 tert-amyl tert-amyl

C-109 H H H

Preferred compounds C are C-1 to C-90. Further, most preferred iscompound C-109.

Cpd. R³ R² R⁵ = R⁶ = R⁸ D-1  —CH₃ —CH₃ H D-2  —CH₂CH₃ —CH₂CH₃ H D-3 n-propyl n-propyl H D-4  iso-propyl iso-propyl H D-5  sec-butylsec-butyl H D-6  iso-butyl iso-butyl H D-7  neopentyl Neopentyl H D-8 

H D-9 

H D-10 —CH₃ —CH₃ —CH₃ D-11 —CH₂CH₃ —CH₂CH₃ —CH₃ D-12 n-propyl n-propyl—CH₃ D-13 iso-propyl iso-propyl —CH₃ D-14 sec-butyl sec-butyl —CH₃ D-15iso-butyl iso-butyl —CH₃ D-16 neopentyl Neopentyl —CH₃ D-17

—CH₃ D-18

—CH₃ D-19 —CH₃ —CH₃ —CH₂CH₃ D-20 —CH₂CH₃ —CH₂CH₃ —CH₂CH₃ D-21 n-propyln-propyl —CH₂CH₃ D-22 iso-propyl iso-propyl —CH₂CH₃ D-23 sec-butylsec-butyl —CH₂CH₃ D-24 iso-butyl iso-butyl —CH₂CH₃ D-25 neopentylNeopentyl —CH₂CH₃ D-26

—CH₂CH₃ D-27

—CH₂CH₃ D-28 —CH₃ —CH₃ n-propyl D-29 —CH₂CH₃ —CH₂CH₃ n-propyl D-30n-propyl n-propyl n-propyl D-31 iso-propyl iso-propyl n-propyl D-32sec-butyl sec-butyl n-propyl D-33 iso-butyl iso-butyl n-propyl D-34neopentyl Neopentyl n-propyl D-35

n-propyl D-36

n-propyl D-37 —CH₃ —CH₃ iso-propyl D-38 —CH₂CH₃ —CH₂CH₃ iso-propyl D-39n-propyl n-propyl iso-propyl D-40 iso-propyl iso-propyl iso-propyl D-41sec-butyl sec-butyl iso-propyl D-42 iso-butyl iso-butyl iso-propyl D-43neopentyl Neopentyl iso-propyl D-44

iso-propyl D-45

iso-propyl D-46 —CH₃ —CH₃ sec-butyl D-47 —CH₂CH₃ —CH₂CH₃ sec-butyl D-48n-propyl n-propyl sec-butyl D-49 iso-propyl iso-propyl sec-butyl D-50sec-butyl sec-butyl sec-butyl D-51 iso-butyl iso-butyl sec-butyl D-52neopentyl Neopentyl sec-butyl D-53

sec-butyl D-54

sec-butyl D-55 —CH₃ —CH₃ iso-butyl D-56 —CH₂CH₃ —CH₂CH₃ iso-butyl D-57n-propyl n-propyl iso-butyl D-58 iso-propyl iso-propyl iso-butyl D-59sec-butyl sec-butyl iso-butyl D-60 iso-propyl iso-propyl iso-butyl D-61neopentyl Neopentyl iso-butyl D-62

iso-butyl D-63

iso-butyl D-64 —CH₃ —CH₃ neopentyl D-65 —CH₂CH₃ —CH₂CH₃ neopentyl D-66n-propyl n-propyl neopentyl D-67 iso-propyl iso-propyl neopentyl D-68sec-butyl sec-butyl neopentyl D-69 iso-butyl iso-butyl neopentyl D-70neopentyl Neopentyl neopentyl D-71

neopentyl D-72

neopentyl D-73 —CH₃ —CH₃

D-74 —CH₂CH₃ —CH₂CH₃

D-75 n-propyl n-propyl

D-76 iso-propyl iso-propyl

D-77 sec-butyl sec-butyl

D-78 iso-butyl iso-butyl

D-79 neopentyl Neopentyl

D-80

D-81

D-82 —CH₃ —CH₃

D-83 —CH₂CH₃ —CH₂CH₃

D-84 n-propyl n-propyl

D-85 iso-propyl iso-propyl

D-86 sec-butyl sec-butyl

D-87 iso-butyl iso-butyl

D-88 neopentyl Neopentyl

D-89

D-90

Cpd. R⁴ R¹ R⁵ E-1, E′-1, E″-1, E′′′-1, E′′′′-1, E′′′′′-1 —CH₃ —CH₃ HE-2, E′-2, E″-2, E′′′-2, E′′′′-2, E′′′′′-2 —CH₂CH₃ —CH₂CH₃ H E-3, E′-3,E″-3, E′′′-3, E-′′′′-3, E′′′′′-3 n-propyl n-propyl H E-4, E′-4, E″-4,E′′′-4, E′′′′-4, E′′′′′-4 iso-propyl iso-propyl H E-5, E′-5, E″-5,E′′′-5, E′′′′-5, E′′′′′-5 sec-butyl sec-butyl H E-6, E′-6, E″-6, E′′′-6,E′′′′-6, E′′′′′-6 iso-butyl iso-butyl H E-7, E′-7, E″-7, E′′′-7,E′′′′-7, E′′′′′-7 neopentyl neopentyl H E-8, E′-8, E″-8, E′′′-8,E′′′′-8, E′′′′′-8

H E-9, E′-9, E″-9, E′′′-9, E′′′′-9, E′′′′′-9

H E-10, E′-10, E″-10, E′′′-10, E′′′′-10, E′′′′′-10 —CH₃ —CH₃ —CH₃ E-11,E′-11, E″-11, E′′′-11, E′′′′-11, E′′′′′-11 —CH₂CH₃ —CH₂CH₃ —CH₃ E-12,E′-12, E″-12, E′′′-12, E′′′′-12, E′′′′′-12 n-propyl n-propyl —CH₃ E-13,E′-13, E″-13, E′′′-13, E′′′′-13, E′′′′′-13 iso-propyl iso-propyl —CH₃E-14, E′-14, E″-14, E′′′-14, E′′′′-14, E′′′′′-14 sec-butyl sec-butyl—CH₃ E-15, E′-15, E″-15, E′′′-15, E′′′′-15, E′′′′′-15 iso-butyliso-butyl —CH₃ E-16, E′-16, E″-16, E′′′-16, E′′′′-16, E′′′′′-16neopentyl neopentyl —CH₃ E-17, E′-17, E″-17, E′′′-17, E′′′′-17,E′′′′′-17

—CH₃ E-18, E′-18, E″-18, E′′′-18, E′′′′-18, E′′′′′-18

—CH₃ E-19, E′-19, E″-19, E′′′-19, E′′′′-19, E′′′′′-19 —CH₃ —CH₃ —CH₂CH₃E-20, E′-20, E″-20, E′′′-20, E′′′′-20, E′′′′′-20 —CH₂CH₃ —CH₂CH₃ —CH₂CH₃E-21, E′-21, E″-21, E′′′-21, E′′′′-21, E′′′′′-21 n-propyl n-propyl—CH₂CH₃ E-22, E′-22, E″-22, E′′′-22, E′′′′-22, E′′′′′-22 iso-propyliso-propyl —CH₂CH₃ E-23, E′-23, E″-23, E′′′-23, E′′′′-23, E′′′′′-23sec-butyl sec-butyl —CH₂CH₃ E-24, E′-24, E″-24, E′′′-24, E′′′′-24,E′′′′′-24 iso-butyl iso-butyl —CH₂CH₃ E-25, E′-25, E″-25, E′′′-25,E′′′′-25, E′′′′′-25 neopentyl neopentyl —CH₂CH₃ E-26, E′-26, E″-26,E′′′-26, E′′′′-26, E′′′′′-26

—CH₂CH₃ E-27, E′-27, E″-27, E′′′-27, E′′′′-27, E′′′′′-27

—CH₂CH₃ E-28, E′-28, E″-28, E′′′-28, E′′′′-28, E′′′′′-28 —CH₃ —CH₃n-propyl E-29, E′-29, E″-29, E′′′-29, E′′′′-29, E′′′′′-29 —CH₂CH₃—CH₂CH₃ n-propyl E-30, E′-30, E″-30, E′′′-30, E′′′′-30, E′′′′′-30n-propyl n-propyl n-propyl E-31, E′-31, E″-31, E′′′-31, E′′′′-31,E′′′′′-31 iso-propyl iso-propyl n-propyl E-32, E′-32, E″-32, E′′′-32,E′′′′-32, E′′′′′-32 sec-butyl sec-butyl n-propyl E-33, E′-33, E″-33,E′′′-33, E′′′′-33, E′′′′′-33 iso-butyl iso-butyl n-propyl E-34, E′-34,E″-34, E′′′-34, E′′′′-34, E′′′′′-34 neopentyl neopentyl n-propyl E-35,E′-35, E″-35, E′′′-35, E′′′′-35, E′′′′′-35

n-propyl E-36, E′-36, E″-36, E′′′-36, E′′′′-36, E′′′′′-36

n-propyl E-37, E′-37, E″-37, E′′′-37, E′′′′-37, E′′′′′-37 —CH₃ —CH₃iso-propyl E-38, E′-38, E″-38, E′′′-38, E′′′′-38, E′′′′′-38 —CH₂CH₃—CH₂CH₃ iso-propyl E-39, E′-39, E″-39, E′′′-39, E′′′′-39, E′′′′′-39n-propyl n-propyl iso-propyl E-40, E′-40, E″-40, E′′′-40, E′′′′-40,E′′′′′-40 iso-propyl iso-propyl iso-propyl E-41, E′-41, E″-41, E′′′-41,E′′′′-41, E′′′′′-41 sec-butyl sec-butyl iso-propyl E-42, E′-42, E″-42,E′′′-42, E′′′′-42, E′′′′′-42 iso-butyl iso-butyl iso-propyl E-43, E′-43,E″-43, E′′′-43, E′′′′-43, E′′′′′-43 neopentyl neopentyl iso-propyl E-44,E′-44, E″-44, E′′′-44, E′′′′-44, E′′′′′-44

iso-propyl E-45, E′-45, E″-45, E′′′-45, E′′′′-45, E′′′′′-45

iso-propyl E-46, E′-46, E″-46 E′′′-46, E′′′′-46, E′′′′′-46 —CH₃ —CH₃sec-butyl E-47, E′-47, E″-47, E′′′-47, E′′′′-47, E′′′′′-47 —CH₂CH₃—CH₂CH₃ sec-butyl E-48, E′-48, E″-48, E′′′-48, E′′′′-48, E′′′′′-48n-propyl n-propyl sec-butyl E-49, E′-49, E″-49, E′′′-49, E′′′′-49,E′′′′′-49 iso-propyl iso-propyl sec-butyl E-50, E′-50, E″-50, E′′′-50,E′′′′-50, E′′′′′-50 sec-butyl sec-butyl sec-butyl E-51, E′-51, E″-51,E′′′-51, E′′′′-51, E′′′′′-51 iso-butyl iso-butyl sec-butyl E-52, E′-52,E″-52, E′′′-52, E′′′′-52, E′′′′′-52 neopentyl neopentyl sec-butyl E-53,E′-53, E″-53, E′′′-53, E′′′′-53, E′′′′′-53

sec-butyl E-54, E′-54, E″-54, E′′′-54, E′′′′-54, E′′′′′-54

sec-butyl E-55, E′-55, E″-55, E′′′-55, E′′′′-55, E′′′′′-55 —CH₃ —CH₃iso-butyl E-56, E′-56, E″-56, E′′′-56, E′′′′-56, E′′′′′-56 —CH₂CH₃—CH₂CH₃ iso-butyl E-57, E′-57, E″-57, E′′′-57, E′′′′-57, E′′′′′-57n-propyl n-propyl iso-butyl E-58, E′-58, E″-58, E′′′-58, E′′′′-58,E′′′′′-58 iso-propyl iso-propyl iso-butyl E-59, E′-59, E″-59, E′′′-59,E′′′′-59, E′′′′′-59 sec-butyl sec-butyl iso-butyl E-60, E′-60, E″-60,E′′′-60, E′′′′-60, E′′′′′-60 iso-butyl iso-butyl iso-butyl E-61, E′-61,E″-61, E′′′-61, E′′′′-61, E′′′′′-61 neopentyl neopentyl iso-butyl E-62,E′-62, E″-62, E′′′-62, E′′′′-62, E′′′′′-62

iso-butyl E-63, E′-63, E″-63, E′′′-63, E′′′′-63, E′′′′′-63

iso-butyl E-64, E′-64, E″-64, E′′′-64, E′′′′-64, E′′′′′-64 —CH₃ —CH₃neopentyl E-65, E′-65, E″-65, E′′′-65, E′′′′-65, E′′′′′-65 —CH₂CH₃—CH₂CH₃ neopentyl E-66, E′-66, E″-66, E′′′-66, E′′′′-66, E′′′′′-66n-propyl n-propyl neopentyl E-67, E′-67, E″-67, E′′′-67, E′′′′-67,E′′′′′-67 iso-propyl iso-propyl neopentyl E-68, E′-68, E″-68, E′′′-68,E′′′′-68, E′′′′′-68 sec-butyl sec-butyl neopentyl E-69, E′-69, E″-69,E′′′-69, E′′′′-69, E′′′′′-69 iso-butyl iso-butyl neopentyl E-70, E′-70,E″-70, E′′′-70, E′′′′-70, E′′′′′-70 neopentyl neopentyl neopentyl E-71,E′-71, E″-71, E′′′-71, E′′′′-71, E′′′′′-71

neopentyl E-72, E′-72, E″-72, E′′′-72, E′′′′-72, E′′′′′-72

neopentyl E-73, E′-73, E″-73, E′′′-73, E′′′′-73, E′′′′′-73 —CH₃ —CH₃

E-74, E′-74, E″-74, E′′′-74, E′′′′-74, E′′′′′-74 —CH₂CH₃ —CH₂CH₃

E-75, E′-75, E″-75, E′′′-75, E′′′′-75, E′′′′′-75 n-propyl n-propyl

E-76, E′-76, E″-76, E′′′-76, E′′′′-76, E′′′′′-76 iso-propyl iso-propyl

E-77, E′-77, E″-77, E′′′-77, E′′′′-77, E′′′′′-77 sec-butyl sec-butyl

E-78, E′-78, E″-78, E′′′-78, E′′′′-78, E′′′′′-78 iso-butyl iso-butyl

E-79, E′-79, E″-79, E′′′-79, E′′′′-79, E′′′′′-79 neopentyl neopentyl

E-80, E′-80, E″-80, E′′′-80, E′′′′-80, E′′′′′-80

E-81, E′-81, E″-81, E′′′-81, E′′′′-81, E′′′′′-81

E-82, E′-82, E″-82, E′′′-82, E′′′′-82, E′′′′′-82 —CH₃ —CH₃

E-83, E′-83, E″-83, E′′′-83, E′′′′-83, E′′′′′-83 —CH₂CH₃ —CH₂CH₃

E-84, E′-84, E″-84, E′′′-84, E′′′′-84, E′′′′′-84 n-propyl n-propyl

E-85, E′-85, E″-85, E′′′-85, E′′′′-85, E′′′′′-85 iso-propyl iso-propyl

E-86, E′-86, E″-86, E′′′-86, E′′′′-86, E′′′′′-86 sec-butyl sec-butyl

E-87, E′-87, E″-87, E′′′-87, E′′′′-87, E′′′′′-87 iso-butyl iso-butyl

E-88, E′-88, E″-88, E′′′-88, E′′′′-88, E′′′′′-88 neopentyl neopentyl

E-89, E′-89, E″-89, E′′′-89, E′′′′-89, E′′′′′-89

E-90, E′-90, E″-90, E′′′-90, E′′′′-90, E′′′′′-90

E-91, E′-91, E″-91, E′′′-91, E′′′′-91, E′′′′′-91 —CH₃ —CH₃ tert-butylE-92, E′-92, E″-92, E′′′-92, E′′′′-92, E′′′′′-92 —CH₂CH₃ —CH₂CH₃tert-butyl E-93, E′-93, E″-93, E′′′-93, E′′′′-93, E′′′′′-93 n-propyln-propyl tert-butyl E-94, E′-94, E″-94, E′′′-94, E′′′′-94, E′′′′′-94iso-propyl iso-propyl tert-butyl E-95, E′-95, E″-95, E′′′-95, E′′′′-95,E′′′′′-95 sec-butyl sec-butyl tert-butyl E-96, E′-96, E″-96, E′′′-96,E′′′′-96, E′′′′′-96 iso-butyl iso-butyl tert-butyl E-97, E′-97, E″-97,E′′′-97, E′′′′-97, E′′′′′-97 neopentyl neopentyl tert-butyl E-98, E′-98,E″-98, E′′′-98, E′′′′-98, E′′′′′-98

tert-butyl E-99, E′-99, E″-99, E′′′-99, E′′′′-99, E′′′′′-99

tert-butyl E-100, E′-100, E″-100, E′′′-100, E′′′′-100, E′′′′′-100 —CH₃—CH₃ tert-amyl E-101, E′-101, E″-101, E′′′-101, E′′′′-101, E′′′′′-101—CH₂CH₃ —CH₂CH₃ tert-amyl E-102, E′-102, E″-102, E′′′-102, E′′′′-102,E′′′′′-102 n-propyl n-propyl tert-amyl E-103, E′-103, E″-103, E′′′-103,E′′′′-103, E′′′′′-103 iso-propyl iso-propyl tert-amyl E-104, E′-104,E″-104, E′′′-104, E′′′′-104, E′′′′′-104 sec-butyl sec-butyl tert-amylE-105, E′-105, E″-105, E′′′-105, E′′′′-105, E′′′′′-105 iso-butyliso-butyl tert-amyl E-106, E′-106, E″-106, E′′′-106, E′′′′-106,E′′′′′-106 neopentyl neopentyl tert-amyl E-107, E′-107, E″-107,E′′′-107, E′′′′-107, E′′′′′-107

tert-amyl E-108, E′-108, E″-108, E′′′-108, E′′′′-108, E′′′′′-108

tert-amyl E-109, E′-109, E″-109, E′′′-109, E′′′′-109, E′′′′′-109tert-butyl tert-butyl —CH₃ E-110, E′-110, E″-110, E′′′-110, E′′′′-110,E′′′′′-110 tert-butyl tert-butyl —CH₂CH₃ E-111, E′-111, E″-111,E′′′-111, E′′′′-111, E′′′′′-111 tert-butyl tert-butyl n-propyl E-112,E′-112, E″-112, E′′′-112, E′′′′-112, E′′′′′-112 tert-butyl tert-butyliso-propyl E-113, E′-113, E″-113, E′′′-113, E′′′′-113, E′′′′′-113tert-butyl tert-butyl sec-butyl E-114, E′-114, E″-114, E′′′-114,E′′′′-114, E′′′′′-114 tert-butyl tert-butyl iso-butyl E-115, E′-115,E″-115, E′′′-115, E′′′′-115, E′′′′′-115 tert-butyl tert-butyl neopentylE-116, E′-116, E″-116, E′′′-116, E′′′′-116, E′′′′′-116 tert-butyltert-butyl

E-117, E′-117, E″-117, E′′′-117, E′′′′-117, E′′′′′-117 tert-butyltert-butyl

E-118, E′-118, E″-118, E′′′-118, E′′′′-118, E′′′′′-118 tert-butyltert-butyl tert-butyl E-119, E′-119, E″-119, E′′′-119, E′′′′-119,E′′′′′-119 tert-butyl tert-butyl tert-amyl E-120, E′-120, E″-120,E′′′-120, E′′′′-120, E′′′′′-120 tert-amyl tert-amyl —CH₃ E-121, E′-121,E″-121, E′′′-121, E′′′′-121, E′′′′′-121 tert-amyl tert-amyl —CH₂CH₃E-122, E′-122, E″-122, E′′′-122, E′′′′-122, E′′′′′-122 tert-amyltert-amyl n-propyl E-123, E′-123, E″-123, E′′′-123, E′′′′-123,E′′′′′-123 tert-amyl tert-amyl iso-propyl E-124, E′-124, E″-124,E′′′-124, E′′′′-124, E′′′′′-124 tert-amyl tert-amyl sec-butyl E-125,E′-125, E″-125, E′′′-125, E′′′′-125, E′′′′′-125 tert-amyl tert-amyliso-butyl E-126, E′-126, E″-126, E′′′-126, E′′′′-126, E′′′′′-126tert-amyl tert-amyl neopentyl E-127, E′-127, E″-127, E′′′-127,E′′′′-127, E′′′′′-127 tert-amyl tert-amyl

E-128, E′-128, E″-128, E′′′-128, E′′′′-128, E′′′′′-128 tert-amyltert-amyl

E-129, E′-129, E″-129, E′′′-129, E′′′′-129, E′′′′′-129 tert-amyltert-amyl tert-butyl E-130, E′-130, E″-130, E′′′-130, E′′′′-130,E′′′′′-130 tert-amyl tert-amyl tert-amyl

Preferred compounds E, E′, E″, E″′, E″″ and E″″′ are compounds E-1,E′-1, E″-1, E′″-1, E-1″″ and E″′″-1 to E-90, E′-90, E″-90, E″′-90,E″″-90 and E″′″-90.

Cpd. R³ R² R⁵ F-1, F′-1, F″-1, F′′′-1, F′′′′-1, F′′′′′-1 —CH₃ —CH₃ HF-2, F′-2, F″-2, F′′′-2, F′′′′-2, F′′′′′-2 —CH₂CH₃ —CH₂CH₃ H F-3, F′-3,F″-3, F′′′-3, F-′′′′-3, F′′′′′-3 n-propyl n-propyl H F-4, F′-4, F″-4,F′′′-4, F′′′′-4, F′′′′′-4 iso-propyl iso-propyl H F-5, F′-5, F″-5,F′′′-5, F′′′′-5, F′′′′′-5 sec-butyl sec-butyl H F-6, F′-6, F″-6, F′′′-6,F′′′′-6, F′′′′′-6 iso-butyl iso-butyl H F-7, F′-7, F″-7, F′′′-7,F′′′′-7, F′′′′′-7 neopentyl neopentyl H F-8, F′-8, F″-8, F′′′-8,F′′′′-8, F′′′′′-8

H F-9, F′-9, F″-9, F′′′-9, F′′′′-9, F′′′′′-9

H F-10, F′-10, F″-10, F′′′-10, F′′′′-10, F′′′′′-10 —CH₃ —CH₃ —CH₃ F-11,F′-11, F″-11, F′′′-11, F′′′′-11, F′′′′′-11 —CH₂CH₃ —CH₂CH₃ —CH₃ F-12,F′-12, F″-12, F′′′-12, F′′′′-12, F′′′′′-12 n-propyl n-propyl —CH₃ F-13,F′-13, F″-13, F′′′-13, F′′′′-13, F′′′′′-13 iso-propyl iso-propyl —CH₃F-14, F′-14, F″-14, F′′′-14, F′′′′-14, F′′′′′-14 sec-butyl sec-butyl—CH₃ F-15, F′-15, F″-15, F′′′-15, F′′′′-15, F′′′′′-15 iso-butyliso-butyl —CH₃ F-16, F′-16, F″-16, F′′′-16, F′′′′-16, F′′′′′-16neopentyl neopentyl —CH₃ F-17, F′-17, F″-17, F′′′-17, F′′′′-17,F′′′′′-17

—CH₃ F-18, F′-18, F″-18, F′′′-18, F′′′′-18, F′′′′′-18

—CH₃ F-19, F′-19, F″-19, F′′′-19, F′′′′-19, F′′′′′-19 —CH₃ —CH₃ —CH₂CH₃F-20, F′-20, F″-20, F′′′-20, F′′′′-20, F′′′′′-20 —CH₂CH₃ —CH₂CH₃ —CH₂CH₃F-21, F′-21, F″-21, F′′′-21, F′′′′-21, F′′′′′-21 n-propyl n-propyl—CH₂CH₃ F-22, F′-22, F″-22, F′′′-22, F′′′′-22, F′′′′′-22 iso-propyliso-propyl —CH₂CH₃ F-23, F′-23, F″-23, F′′′-23, F′′′′-23, F′′′′′-23sec-butyl sec-butyl —CH₂CH₃ F-24, F′-24, F″-24, F′′′-24, F′′′′-24,F′′′′′-24 iso-butyl iso-butyl —CH₂CH₃ F-25, F′-25, F″-25, F′′′-25,F′′′′-25, F′′′′′-25 neopentyl neopentyl —CH₂CH₃ F-26, F′-26, F″-26,F′′′-26, F′′′′-26, F′′′′′-26

—CH₂CH₃ F-27, F′-27, F″-27, F′′′-27, F′′′′-27, F′′′′′-27

—CH₂CH₃ F-28, F′-28, F″-28, F′′′-28, F′′′′-28, F′′′′′-28 —CH₃ —CH₃n-propyl F-29, F′-29, F″-29, F′′′-29, F′′′′-29, F′′′′′-29 —CH₂CH₃—CH₂CH₃ n-propyl F-30, F′-30, F″-30, F′′′-30, F′′′′-30, F′′′′′-30n-propyl n-propyl n-propyl F-31, F′-31, F″-31, F′′′-31, F′′′′-31,F′′′′′-31 iso-propyl iso-propyl n-propyl F-32, F′-32, F″-32, F′′′-32,F′′′′-32, F′′′′′-32 sec-butyl sec-butyl n-propyl F-33, F′-33, F″-33,F′′′-33, F′′′′-33, F′′′′′-33 iso-butyl iso-butyl n-propyl F-34, F′-34,F″-34, F′′′-34, F′′′′-34, F′′′′′-34 neopentyl neopentyl n-propyl F-35,F′-35, F″-35, F′′′-35, F′′′′-35, F′′′′′-35

n-propyl F-36, F′-36, F″-36, F′′′-36, F′′′′-36, F′′′′′-36

n-propyl F-37, F′-37, F″-37, F′′′-37, F′′′′-37, F′′′′′-37 —CH₃ —CH₃iso-propyl F-38, F′-38, F″-38, F′′′-38, F′′′′-38, F′′′′′-38 —CH₂CH₃—CH₂CH₃ iso-propyl F-39, F′-39, F″-39, F′′′-39, F′′′′-39, F′′′′′-39n-propyl n-propyl iso-propyl F-40, F′-40, F″-40, F′′′-40, F′′′′-40,F′′′′′-40 iso-propyl iso-propyl iso-propyl F-41, F′-41, F″-41, F′′′-41,F′′′′-41, F′′′′′-41 sec-butyl sec-butyl iso-propyl F-42, F′-42, F″-42,F′′′-42, F′′′′-42, F′′′′′-42 iso-butyl iso-butyl iso-propyl F-43, F′-43,F″-43, F′′′-43, F′′′′-43, F′′′′′-43 neopentyl neopentyl iso-propyl F-44,F′-44, F″-44, F′′′-44, F′′′′-44, F′′′′′-44

iso-propyl F-45, F′-45, F″-45, F′′′-45, F′′′′-45, F′′′′′-45

iso-propyl F-46, F′-46, F″-46 F′′′-46, F′′′′-46, F′′′′′-46 —CH₃ —CH₃sec-butyl F-47, F′-47, F″-47, F′′′-47, F′′′′-47, F′′′′′-47 —CH₂CH₃—CH₂CH₃ sec-butyl F-48, F′-48, F″-48, F′′′-48, F′′′′-48, F′′′′′-48n-propyl n-propyl sec-butyl F-49, F′-49, F″-49, F′′′-49, F′′′′-49,F′′′′′-49 iso-propyl iso-propyl sec-butyl F-50, F′-50, F″-50, F′′′-50,F′′′′-50, F′′′′′-50 sec-butyl sec-butyl sec-butyl F-51, F′-51, F″-51,F′′′-51, F′′′′-51, F′′′′′-51 iso-butyl iso-butyl sec-butyl F-52, F′-52,F″-52, F′′′-52, F′′′′-52, F′′′′′-52 neopentyl neopentyl sec-butyl F-53,F′-53, F″-53, F′′′-53, F′′′′-53, F′′′′′-53

sec-butyl F-54, F′-54, F″-54, F′′′-54, F′′′′-54, F′′′′′-54

sec-butyl F-55, F′-55, F″-55, F′′′-55, F′′′′-55, F′′′′′-55 —CH₃ —CH₃iso-butyl F-56, F′-56, F″-56, F′′′-56, F′′′′-56, F′′′′′-56 —CH₂CH₃—CH₂CH₃ iso-butyl F-57, F′-57, F″-57, F′′′-57, F′′′′-57, F′′′′′-57n-propyl n-propyl iso-butyl F-58, F′-58, F″-58, F′′′-58, F′′′′-58,F′′′′′-58 iso-propyl iso-propyl iso-butyl F-59, F′-59, F″-59, F′′′-59,F′′′′-59, F′′′′′-59 sec-butyl sec-butyl iso-butyl F-60, F′-60, F″-60,F′′′-60, F′′′′-60, F′′′′′-60 iso-butyl iso-butyl iso-butyl F-61, F′-61,F″-61, F′′′-61, F′′′′-61, F′′′′′-61 neopentyl neopentyl iso-butyl F-62,F′-62, F″-62, F′′′-62, F′′′′-62, F′′′′′-62

iso-butyl F-63, F′-63, F″-63, F′′′-63, F′′′′-63, F′′′′′-63

iso-butyl F-64, F′-64, F″-64, F′′′-64, F′′′′-64, F′′′′′-64 —CH₃ —CH₃Neopentyl F-65, F′-65, F″-65, F′′′-65, F′′′′-65, F′′′′′-65 —CH₂CH₃—CH₂CH₃ Neopentyl F-66, F′-66, F″-66, F′′′-66, F′′′′-66, F′′′′′-66n-propyl n-propyl Neopentyl F-67, F′-67, F″-67, F′′′-67, F′′′′-67,F′′′′′-67 iso-propyl iso-propyl Neopentyl F-68, F′-68, F″-68, F′′′-68,F′′′′-68, F′′′′′-68 sec-butyl sec-butyl Neopentyl F-69, F′-69, F″-69,F′′′-69, F′′′′-69, F′′′′′-69 iso-butyl iso-butyl neopentyl F-70, F′-70,F″-70, F′′′-70, F′′′′-70, F′′′′′-70 neopentyl neopentyl Neopentyl F-71,F′-71, F″-71, F′′′-71, F′′′′-71, F′′′′′-71

Neopentyl F-72, F′-72, F″-72, F′′′-72, F′′′′-72, F′′′′′-72

Neopentyl F-73, F′-73, F″-73, F′′′-73, F′′′′-73, F′′′′′-73 —CH₃ —CH₃

F-74, F′-74, F″-74, F′′′-74, F′′′′-74, F′′′′′-74 —CH₂CH₃ —CH₂CH₃

F-75, F′-75, F″-75, F′′′-75, F′′′′-75, F′′′′′-75 n-propyl n-propyl

F-76, F′-76, F″-76, F′′′-76, F′′′′-76, F′′′′′-76 iso-propyl iso-propyl

F-77, F′-77, F″-77, F′′′-77, F′′′′-77, F′′′′′-77 sec-butyl sec-butyl

F-78, F′-78, F″-78, F′′′-78, F′′′′-78, F′′′′′-78 iso-butyl iso-butyl

F-79, F′-79, F″-79, F′′′-79, F′′′′-79, F′′′′′-79 neopentyl neopentyl

F-80, F′-80, F″-80, F′′′-80, F′′′′-80, F′′′′′-80

F-81, F′-81, F″-81, F′′′-81, F′′′′-81, F′′′′′-81

F-82, F′-82, F″-82, F′′′-82, F′′′′-82, F′′′′′-82 —CH₃ —CH₃

F-83, F′-83, F″-83, F′′′-83, F′′′′-83, F′′′′′-83 —CH₂CH₃ —CH₂CH₃

F-84, F′-84, F″-84, F′′′-84, F′′′′-84, F′′′′′-84 n-propyl n-propyl

F-85, F′-85, F″-85, F′′′-85, F′′′′-85, F′′′′′-85 iso-propyl iso-propyl

F-86, F′-86, F″-86, F′′′-86, F′′′′-86, F′′′′′-86 sec-butyl sec-butyl

F-87, F′-87, F″-87, F′′′-87, F′′′′-87, F′′′′′-87 iso-butyl iso-butyl

F-88, F′-88, F″-88, F′′′-88, F′′′′-88, F′′′′′-88 neopentyl neopentyl

F-89, F′-89, F″-89, F′′′-89, F′′′′-89, F′′′′′-89

F-90, F′-90, F″-90, F′′′-90, F′′′′-90, F′′′′′-90

F-91, F′-91, F″-91, F′′′-91, F′′′′-91, F′′′′′-91 —CH₃ —CH₃ tert-butylF-92, F′-92, F″-92, F′′′-92, F′′′′-92, F′′′′′-92 —CH₂CH₃ —CH₂CH₃tert-butyl F-93, F′-93, F″-93, F′′′-93, F′′′′-93, F′′′′′-93 n-propyln-propyl tert-butyl F-94, F′-94, F″-94, F′′′-94, F′′′′-94, F′′′′′-94iso-propyl iso-propyl tert-butyl F-95, F′-95, F″-95, F′′′-95, F′′′′-95,F′′′′′-95 sec-butyl sec-butyl tert-butyl F-96, F′-96, F″-96, F′′′-96,F′′′′-96, F′′′′′-96 iso-butyl iso-butyl tert-butyl F-97, F′-97, F″-97,F′′′-97, F′′′′-97, F′′′′′-97 neopentyl neopentyl tert-butyl F-98, F′-98,F″-98, F′′′-98, F′′′′-98, F′′′′′-98

tert-butyl F-99, F′-99, F″-99, F′′′-99, F′′′′-99, F′′′′′-99

tert-butyl F-100, F′-100, F″-100, F′′′-100, F′′′′-100, F′′′′′-100 —CH₃—CH₃ tert-amyl F-101, F′-101, F″-101, F′′′-101, F′′′′-101, F′′′′′-101—CH₂CH₃ —CH₂CH₃ tert-amyl F-102, F′-102, F″-102, F′′′-102, F′′′′-102,F′′′′′-102 n-propyl n-propyl tert-amyl F-103, F′-103, F″-103, F′′′-103,F′′′′-103, F′′′′′-103 iso-propyl iso-propyl tert-amyl F-104, F′-104,F″-104, F′′′-104, F′′′′-104, F′′′′′-104 sec-butyl sec-butyl tert-amylF-105, F′-105, F″-105, F′′′-105, F′′′′-105, F′′′′′-105 iso-butyliso-butyl tert-amyl F-106, F′-106, F″-106, F′′′-106, F′′′′-106,F′′′′′-106 neopentyl neopentyl tert-amyl F-107, F′-107, F″-107,F′′′-107, F′′′′-107, F′′′′′-107

tert-amyl F-108, F′-108, F″-108, F′′′-108, F′′′′-108, F′′′′′-108

tert-amyl

Preferred compounds F, F′, F″, F″′, F″″ and F″″′ are compounds F-1,F′-1, F″-1, F′″-1, F″″-1 and F′″″-1 to F-90, F′-90, F″-90, F′″-90,F″″-90 and F′″″-90.

Cpd. R⁵ = R⁸ R⁶ = R⁹ I-1, I′-1, I″-1, I′′′-1, I′′′′-1, I′′′′′-1, HI-1,HI′-1, HI″-1, —CH₃ H HI′′′-1, HI′′′′-1, HI′′′′′-1 I-2, I′-2, I″-2,I′′′-2, I′′′′-2, I′′′′′-2, HI-2, HI′-2, HI″-2, —CH₂CH₃ H HI′′′-2,HI′′′′-2, HI′′′′′-2 I-3, I′-3, I″-3, I′′′-3, I′′′′-3, I′′′′′-3, HI-3,HI′-3, HI″-3, n-propyl H HI′′′-3, HI′′′′-3, HI′′′′′-3 I-4, I′-4, I″-4,I′′′-4, I′′′′-4, I′′′′′-4, HI-4, HI′-4, HI″-4, iso-propyl H HI′′′-4,HI′′′′-4, HI′′′′′-4 I-5, I′-5, I″-5, I′′′-5, I′′′′-5, I′′′′′-5, HI-5,HI′-5, HI″-5, sec-butyl H HI′′′-5, HI′′′′-5, HI′′′′′-5 I-6, I′-6, I″-6,I′′′-6, I′′′′-6, I′′′′′-6, HI-6, HI′-6, HI″-6, iso-butyl H HI′′′-6,HI′′′′-6, HI′′′′′-6 I-7, I′-7, I″-7, I′′′-7, I′′′′-7, I′′′′′-7, HI-7,HI′-7, HI″-7, neopentyl H HI′′′-7, HI′′′′-7, HI′′′′′-7 I-8, I′-8, I″-8,I′′′-8, I′′′′-8, I′′′′′-8, HI-8, HI′-8, HI″-8, HI′′′-8, HI′′′′-8,HI′′′′′-8

H I-9, I′-9, I″-9, I′′′-9, I′′′′-9, I′′′′′-9, HI-9, HI′-9, HI″-9,HI′′′-9, HI′′′′-9, HI′′′′′-9

H I-10, I′-10, I″-10, I′′′-10, I′′′′-10, I′′′′′-10, HI-10, HI′- H —CH₃10, HI″-10, HI′′′-10, HI′′′′-10, HI′′′′′-10 I-11, I′-11, I″-11, I′′′-11,I′′′′-11, I′′′′′-11, HI-11, HI′- H —CH₂CH₃ 11, HI″-11, HI′′′-11,HI′′′′-11, HI′′′′′-11 I-12, I′-12, I″-12, I′′′-12, I′′′′-12, I′′′′′-12,HI-12, HI′- H n-propyl 12, HI″-12, HI′′′-12, HI′′′′-12, HI′′′′′-12 I-13,I′-13, I″-13, I′′′-13, I′′′′-13, I′′′′′-13, HI-13, HI′- H iso-propyl 13,HI″-13, HI′′′-13, HI′′′′-13, HI′′′′′-13 I-14, I′-14, I″-14, I′′′-14,I′′′′-14, I′′′′′-14, HI-14, HI′- H sec-butyl 14, HI″-14, HI′′′-14,HI′′′′-14, HI′′′′′-14 I-15, I′-15, I″-15, I′′′-15, I′′′′-15, I′′′′′-15,HI-15, HI′- H iso-butyl 15, HI″-15, HI′′′-15, HI′′′′-15, HI′′′′′-15I-16, I′-16, I″-16, I′′′-16, I′′′′-16, I′′′′′-16, HI-16, HI′- Hneopentyl 16, HI″-16, HI′′′-16, HI′′′′-16, HI′′′′′-16 I-17, I′-17,I″-17, I′′′-17, I′′′′-17, I′′′′′-17, HI-17, HI′- 17, HI″-17, HI′′′-17,HI′′′′-17, HI′′′′′-17 H

I-18, I′-18, I″-18, I′′′-18, I′′′′-18, I′′′′′-18, HI-18, HI′- 18,HI″-18, HI′′′-18, HI′′′′-18, HI′′′′′-18 H

I-19, I′-19, I″-19, I′′′-19, I′′′′-19, I′′′′′-19, HI-19, HI′- 19,HI″-19, HI′′′-19, HI′′′′-19, HI′′′′′-19

H I-20, I′-20, I″-20, I′′′-20, I′′′′-20, I′′′′′-20, HI-20, HI′- 20,HI″-20, HI′′′-20, HI′′′′-20, HI′′′′′-20

H I-21, I′-21, I″-21, I′′′-21, I′′′′-21, I′′′′′-21, HI-21, HI′- 21,HI″-21, HI′′′-21, HI′′′′-21, HI′′′′′-21

H I-22, I′-22, I″-22, I′′′-22, I′′′′-22, I′′′′′-22, HI-22, HI′- 22,HI″-22, HI′′′-22, HI′′′′-22, HI′′′′′-22

H I-23, I′-23, I″-23, I′′′-23, I′′′′-23, I′′′′′-23, HI-23, HI′- 23,HI″-23, HI′′′-23, HI′′′′-23, HI′′′′′-23

H I-24, I′-24, I″-24, I′′′-24, I′′′′-24, I′′′′′-24, HI-24, HI′- 24,HI″-24, HI′′′-24, HI′′′′-24, HI′′′′′-24

H I-25, I′-25, I″-25, I′′′-25, I′′′′-25, I′′′′′-25, HI-25, HI′- 25,HI″-25, HI′′′-25, HI′′′′-25, HI′′′′′-25

H I-26, I′-26, I″-26, I′′′-26, I′′′′-26, I′′′′′-26, HI-26, HI′- 26,HI″-26, HI′′′-26, HI′′′′-26, HI′′′′′-26

H I-27, I′-27, I″-27, I′′′-27, I′′′′-27, I′′′′′-27, HI-27, HI′- 27,HI″-27, HI′′′-27, HI′′′′-27, HI′′′′′-27

H I-28, I′-28, I″-28, I′′′-28, I′′′′-28, I′′′′′-28, HI-28, HI′- 28,HI″-28, HI′′′-28, HI′′′′-28, HI′′′′′-28

H I-29, I′-29, I″-29, I′′′-29, I′′′′-29, I′′′′′-29, HI-29, HI′- 29,HI″-29, HI′′′-29, HI′′′′-29, HI′′′′′-29 H

I-30, I′-30, I″-30, I′′′-30, I′′′′-30, I′′′′′-30, HI-30, HI′- 30,HI″-30, HI′′′-30, HI′′′′-30, HI′′′′′-30 H

I-31, I′-31, I″-31, I′′′-31, I′′′′-31, I′′′′′-31, HI-31, HI′- 31,HI″-31, HI′′′-31, HI′′′′-31, HI′′′′′-31 H

I-32, I′-32, I″-32, I′′′-32, I′′′′-32, I′′′′′-32, HI-32, HI′- 32,HI″-32, HI′′′-32, HI′′′′-32, HI′′′′′-32 H

I-33, I′-33, I″-33, I′′′-33, I′′′′-33, I′′′′′-33, HI-33, HI′- 33,HI″-33, HI′′′-33, HI′′′′-33, HI′′′′′-33 H

I-34, I′-34, I″-34, I′′′-34, I′′′′-34, I′′′′′-34, HI-34, HI′- 34,HI″-34, HI′′′-34, HI′′′′-34, HI′′′′′-34 H

I-35, I′-35, I″-35, I′′′-35, I′′′′-35, I′′′′′-35, HI-35, HI′- 35,HI″-35, HI′′′-35, HI′′′′-35, HI′′′′′-35 H

I-36, I′-36, I″-36, I′′′-36, I′′′′-36, I′′′′′-36, HI-36, HI′- 36,HI″-36, HI′′′-36, HI′′′′-36, HI′′′′′-36 H

I-37, I′-37, I″-37, I′′′-37, I′′′′-37, I′′′′′-37, HI-37, HI′- 37,HI″-37, HI′′′-37, HI′′′′-37, HI′′′′′-37 H

I-38, I′-38, I″-38, I′′′-38, I′′′′-38, I′′′′′-38, HI-38, HI′- 38,HI″-38, HI′′′-38, HI′′′′-38, HI′′′′′-38 H

I-39, I′-39, I″-39, I′′′-39, I′′′′-39, I′′′′′-39, HI-39, HI′- H H 39,HI″-39, HI′′′-39, HI′′′′-39, HI′′′′′-39

Cpd. R⁵ = R⁸ R⁶ = R⁹ J′-1, J″-1, J′′′-1, J′′′′-1, J′′′′′-1, HJ′-1,HJ″-1, HJ′′′- —CH₃ H 1, HJ′′′′-1, HJ′′′′′-1 J′-2, J″-2, J′′′-2, J′′′′-2,J′′′′′-2, HJ′-2, HJ″-2, HJ′′′- —CH₂CH₃ H 2, HJ′′′′-2, HJ′′′′′-2 J′-3,J″-3, J′′′-3, J′′′′-3, J′′′′′-3, HJ′-3, HJ″-3, HJ′′′- n-propyl H 3,HJ′′′′-3, HJ′′′′′-3 J′-4, J″-4, J′′′-4, J′′′′-4, J′′′′′-4, HJ′-4, HJ″-4,HJ′′′- iso-propyl H 4, HJ′′′′-4, HJ′′′′′-4 J′-5, J″-5, J′′′-5, J′′′′-5,J′′′′′-5, HJ′-5, HJ″-5, HJ′′′- sec-butyl H 5, HJ′′′′-5, HJ′′′′′-5 J′-6,J″-6, J′′′-6, J′′′′-6, J′′′′′-6, HJ′-6, HJ″-6, HJ′′′- iso-butyl H 6,HJ′′′′-6, HJ′′′′′-6 J′-7, J″-7, J′′′-7, J′′′′-7, J′′′′′-7, HJ′-7, HJ″-7,HJ′′′- neopentyl H 7, HJ′′′′-7, HJ′′′′′-7 J′-8, J″-8, J′′′-8, J′′′′-8,J′′′′′-8, HJ′-8, HJ″-8, HJ′′′- 8, HJ′′′′-8, HJ′′′′′-8

H J′-9, J″-9, J′′′-9, J′′′′-9, J′′′′′-9, HJ′-9, HJ″-9, HJ′′′- 9,HJ′′′′-9, HJ′′′′′-9

H J′-10, J″-10, J′′′-10, J′′′′-10, J′′′′′-10, HJ′-10, HJ″- H —CH₃ 10,HJ′′′-10, HJ′′′′-10, HJ′′′′′-10 J′-11, J″-11, J′′′-11, J′′′′-11,J′′′′′-11, HJ′-11, HJ″- H —CH₂CH₃ 11, HJ′′′-11, HJ′′′′-11, HJ′′′′′-11J′-12, J″-12, J′′′-12, J′′′′-12, J′′′′′-12, HJ′-12, HJ″- H n-propyl 12,HJ′′′-12, HJ′′′′-12, HJ′′′′′-12 J′-13, J″-13, J′′′-13, J′′′′-13,J′′′′′-13, HJ′-13, HJ″- H iso-propyl 13, HJ′′′-13, HJ′′′′-13, HJ′′′′′-13J′-14, J″-14, J′′′-14, J′′′′-14, J′′′′′-14, HJ′-14, HJ″- H sec-butyl 14,HJ′′′-14, HJ′′′′-14, HJ′′′′′-14 J′-15, J″-15, J′′′-15, J′′′′-15,J′′′′′-15, HJ′-15, HJ″- H iso-butyl 15, HJ′′′-15, HJ′′′′-15, HJ′′′′′-15J′-16, J″-16, J′′′-16, J′′′′-16, J′′′′′-16, HJ′-16, HJ″- H neopentyl 16,HJ′′′-16, HJ′′′′-16, HJ′′′′′-16 J′-17, J″-17, J′′′-17, J′′′′-17,J′′′′′-17, HJ′-17, HJ″- 17, HJ′′′-17, HJ′′′′-17, HJ′′′′′-17 H

J′-18, J″-18, J′′′-18, J′′′′-18, J′′′′′-18, HJ′-18, HJ″- 18, HJ′′′-18,HJ′′′′-18, HJ′′′′′-18 H

J′-19, J″-19, J′′′-19, J′′′′-19, J′′′′′-19, HJ′-19, HJ″- 19, HJ′′′-19,HJ′′′′-19, HJ′′′′′-19

H J′-20, J″-20, J′′′-20, J′′′′-20, J′′′′′-20, HJ′-20, HJ″- 20, HJ′′′-20,HJ′′′′-20, HJ′′′′′-20

H J′-21, J″-21, J′′′-21, J′′′′-21, J′′′′′-21, HJ′-21, HJ″- 21, HJ′′′-21,HJ′′′′-21, HJ′′′′′-21

H J′-22, J″-22, J′′′-22, J′′′′-22, J′′′′′-22, HJ′-22, HJ″- 22, HJ′′′-22,HJ′′′′-22, HJ′′′′′-22

H J′-23, J″-23, J′′′-23, J′′′′-23, J′′′′′-23, HJ′-23, HJ″- 23, HJ′′′-23,HJ′′′′-23, HJ′′′′′-23

H J′-24, J″-24, J′′′-24, J′′′′-24, J′′′′′-24, HJ′-24, HJ″- 24, HJ′′′-24,HJ′′′′-24, HJ′′′′′-24

H J′-25, J″-25, J′′′-25, J′′′′-25, J′′′′′-25, HJ′-25, HJ″- 25, HJ′′′-25,HJ′′′′-25, HJ′′′′′-25

H J′-26, J″-26, J′′′-26, J′′′′-26, J′′′′′-26, HJ′-26, HJ″- 26, HJ′′′-26,HJ′′′′-26, HJ′′′′′-26

H J′-27, J″-27, J′′′-27, J′′′′-27, J′′′′′-27, HJ′-27, HJ″- 27, HJ′′′-27,HJ′′′′-27, HJ′′′′′-27

H J′-28, J″-28, J′′′-28, J′′′′-28, J′′′′′-28, HJ′-28, HJ″- 28, HJ′′′-28,HJ′′′′-28, HJ′′′′′-28

H J′-29, J″-29, J′′′-29, J′′′′-29, J′′′′′-29, HJ′-29, HJ″- 29, HJ′′′-29,HJ′′′′-29, HJ′′′′′-29 H

J′-30, J″-30, J′′′-30, J′′′′-30, J′′′′′-30, HJ′-30, HJ″- 30, HJ′′′-30,HJ′′′′-30, HJ′′′′′-30 H

J′-31, J″-31, J′′′-31, J′′′′-31, J′′′′′-31, HJ′-31, HJ″- 31, HJ′′′-31,HJ′′′′-31, HJ′′′′′-31 H

J′-32, J″-32, J′′′-32, J′′′′-32, J′′′′′-32, HJ′-32, HJ″- 32, HJ′′′-32,HJ′′′′-32, HJ′′′′′-32 H

J′-33, J″-33, J′′′-33, J′′′′-33, J′′′′′-33, HJ′-33, HJ″- 33, HJ′′′-33,HJ′′′′-33, HJ′′′′′-33 H

J′-34, J″-34, J′′′-34, J′′′′-34, J′′′′′-34, HJ′-34, HJ″- 34, HJ′′′-34,HJ′′′′-34, HJ′′′′′-34 H

J′-35, J″-35, J′′′-35, J′′′′-35, J′′′′′-35, HJ′-35, HJ″- 35, HJ′′′-35,HJ′′′′-35, HJ′′′′′-35 H

J′-36, J″-36, J′′′-36, J′′′′-36, J′′′′′-36, HJ′-36, HJ″- 36, HJ′′′-36,HJ′′′′-36, HJ′′′′′-36 H

J′-37, J″-37, J′′′-37, J′′′′-37, J′′′′′-37, HJ′-37, HJ″- 37, HJ′′′-37,HJ′′′′-37, HJ′′′′′-37 H

J′-38, J″-38, J′′′-38, J′′′′-38, J′′′′′-38, HJ′-38, HJ″- 38, HJ′′′-38,HJ′′′′-38, HJ′′′′′-38 H

J′-39, J″-39, J′′′-39, J′′′′-39, J′′′′′-39, HJ′-39, HJ″- H H 39,HJ′′′-39, HJ′′′′-39, HJ′′′′′-39

Examples for most preferred metal carbene complexes of the presentinvention are the following complexes:

Further preferred compounds are

Most preferred compounds are the following compounds

Even more preferred are the following compounds:

Even more preferred are the following compounds:

Even more preferred are the following compounds:

Even more preferred are the following compounds:

Even more preferred are the following compounds:

Preparation of the Inventive Metal Carbene Complexes

(a) Preparation of the Inventive Metal Carbene Complexes

The present invention also relates to a process for preparing theinventive metal carbene complexes, wherein the metal is selected from Irand Pt, comprising at least one ligand of formula (A)

whereinZ is NR^(x), O or S, preferably NR^(x) or O, more preferably NR^(x),R^(x) is

and the other residues, symbols and indices are mentioned above.

In a preferred embodiment, the present invention also relates to aprocess for preparing the inventive metal carbene complexes, wherein themetal is selected from Ir and Pt, comprising at least one ligand offormula (I′)

by contacting suitable compounds comprising Ir or Pt with theappropriate ligands or ligand precursors. The residues R¹, R², R³, R⁴,R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ have been defined before.

In one embodiment of the process according to the invention, a suitablecompound comprising iridium or platinum, preferably iridium, andappropriate carbene ligands, preferably in deprotonated form as the freecarbene or in the form of a protected carbene, for example as thesilver-carbene complex, are contacted.

The present invention therefore relates—in one embodiment—to a processaccording to the invention wherein the ligand precursor used is acorresponding Ag-carbene complex.

In a further preferred embodiment of the process according to theinvention, the ligand precursors used are organic compounds which arereacted with suitable Ir or Pt comprising compounds. The carbene can bereleased from precursors of the carbene ligands by removing volatilesubstances, for example lower alcohols such as methanol or ethanol, forexample at elevated temperature and/or under reduced pressure and/orusing molecular sieves which bind the alcohol molecules eliminated.Corresponding processes are known to those skilled in the art.

The present invention also relates to the process according to theinvention wherein the ligand precursor used is a compound of the generalformula

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ and Z are asdefined above, andR″ is SiR¹³R¹⁴R¹⁵, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl,whereinR¹³, R¹⁴ and R¹⁵ are independently of each other aryl, heteroaryl,alkyl, cycloalkyl or heterocycloalkyl.

Preferably, the present invention also relates to the process accordingto the invention wherein the ligand precursor used is a compound of thegeneral formula

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ are as definedabove, andR″ is SiR¹³R¹⁴R¹⁵, aryl, heteroaryl, alkyl, cycloalkyl orheterocycloalkyl, whereinR¹³, R¹⁴ and R¹⁵ are independently of each other aryl, heteroaryl,alkyl, cycloalkyl or heterocycloalkyl.

In a particularly preferred embodiment, R″ is alkyl, especiallyC₁-C₂₀alkyl, preferably C₁-C₁₀alkyl, more preferably C₁-C₈alkyl, forexample methyl, ethyl, propyl such as n-propyl, isopropyl, butyl such asn-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl or octyl.

R″ in the compound of the general formula (XXA) and (XX) is mostpreferably methyl or ethyl.

Compounds of the general formula (XXA) and (XX) are generally obtainableby processes known to those skilled in the art. Compounds of the generalformula (XXA) and (XX) can be obtained for example by reacting compoundsof the general formula (XXIAa), preferably by reacting compounds of thegeneral formula (XXIa)

preferably

or the correspondingCl or BF₄ salt of formula

preferably

wherein X is Cl or BF₄,with compounds of the general formula HC(OR″)₃ (XXII), orby reacting compounds of the general formula (XXIAa) or (XXIAb),preferably (XXIa) or (XXIb) in a first step with Vilsmeier reagent((chloromethylene)dimethylammonium chloride) and a sodium salt selectedfrom NaBF₄, NaCl, NaBr or NaI to obtain a compound of formula (XXIAc),preferably (XXIc)

preferably

wherein X is BF₄, Cl, Br or I and in a second step with R″OH or M″OR″,wherein M″ is an alkali metal salt, preferably Na, wherein R, R′, R⁴,R^(4′), R⁵, R⁶ and R⁷ are as defined above and the metal is Ir or Pt,comprising one, two or three bidentate ligands of formula (D).

The reaction of compounds of formula (XXIAa), preferably (XXIa) with thecompounds of the general formula HC(OR″)₃ (XXII) is preferably carriedout in the presence of an ammonium salt. Suitable ammonium salts are forexample ammonium tetrafluoroborate or ammonium halides, e.g. ammoniumchloride. The amount of the ammonium salt in relation to the compound offormula (XXIAa), preferably (XXIa) (100 mol %) is usually 1 mol % to 100mol %.

This preparation of the compounds of the general formula (XXA),preferably (XX) can be effected in the presence or in the absence of asolvent. Suitable solvents are specified below. In one preferredembodiment, the compounds of the general formula (XXA), preferably (XX)are prepared in substance, or the compound of the general formula(XXIIA), preferably (XXII) is added in an excess, such that it functionsas a solvent.

Compounds of the general formulae (XXIA) and (XXIIA), preferably (XXI)and (XXII) are commercially available and/or obtainable by processesknown to those skilled in the art; for example, compounds of the generalformula (XXIA), preferably (XXI) are obtainable by reacting theappropriate chlorides with the appropriate amines.

The compounds of the general formula (XXA), preferably (XX) are preparedgenerally at a temperature of 10 to 150° C., preferably 40 to 120° C.,more preferably 60 to 110° C.

The reaction time is generally 2 to 48 hours, preferably 6 to 24 hours,more preferably 8 to 16 hours.

After the reaction has ended, the desired product can be isolated andpurified by customary processes known to those skilled in the art, forexample filtration, recrystallization, column chromatography, etc.

Appropriate compounds, especially complexes, comprising Ir or Pt,preferably iridium, are known to those skilled in the art. Particularlysuitable compounds comprising platinum or iridium comprise, for example,ligands such as halides, preferably chloride, 1,5-cyclooctadiene (COD),cyclooctene (COE), phosphines, cyanides, alkoxides, pseudohalides and/oralkyl.

Particularly preferred complexes comprising the appropriate metal,especially iridium, are selected from the group consisting of[Ir(COD)Cl]₂, [Ir(COE)₂Cl]₂ IrCl₃×H₂O, Ir(acac)₃, Ir(COD)₂BF₄,Ir(COD)₂BARF (BARF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate)),Pt(COD)Cl₂, Pt(acac)₂, [Pt(C₆H₁₀)Cl₂]₂, K₂PtCl₆, Pt(pyridine)₂Cl₂,[PtMe₂(SMe₂)]₂, Pt(SMe₂)₂Cl₂, Pt(SEt₂)₂Cl₂, Pt(phenanthroline)Cl₂,Pt(NH₃)₂Cl₂ and mixtures thereof.

The carbene ligand precursors are deprotonated, preferably before thereaction, for example, by basic compounds known to those skilled in theart, for example basic metalates, basic metal acetates, acetylacetonatesor alkoxides, or bases such as KO^(t)Bu, NaO^(t)Bu, LiO^(t)Bu, NaH,silylamides, Ag₂O and phosphazene bases. Particular preference is givento deprotonating with Ag₂O to obtain the corresponding Ag-carbene, whichis reacted with the compound comprising M to give the inventivecomplexes.

Particularly preferably, the carbene can be released from precursors ofthe carbene ligands by removing volatile substances, for example loweralcohols.

The process according to the invention for preparing the metal carbenecomplexes comprising at least one ligand of formula (I) according to thepresent invention using the compounds of the general formula (XX) hasthe advantage that the compounds of the general formula (XXA),preferably (XX) are stable intermediates which can be handled readilyand can be isolated under standard laboratory conditions. In addition,the compounds of the general formula (XXA), preferably (XX) are solublein customary organic solvents, such that the preparation of theinventive metal carbene complexes comprising at least one ligand offormula (A), preferably of formula (I) in homogeneous solution ispossible, such that a workup of the desired product, i.e. of the metalcarbene complexes comprising at least one ligand of formula (A),preferably of formula (I) is more readily possible, for example forisolation and/or purification.

The contacting is preferably effected in a solvent. Suitable solventsare known per se to those skilled in the art and are preferably selectedfrom the group consisting of aromatic or aliphatic solvents, for examplebenzene, toluene, xylene or mesitylene, cyclic or acyclic ethers, forexample dioxane or THF, alcohols, esters, amides, ketones, nitriles,halogenated compounds and mixtures thereof. Particularly preferredsolvents are toluene, xylenes, mesitylene and dioxane.

The molar ratio of metal-noncarbene complex used to carbene ligandprecursor used is generally 1:10 to 10:1, preferably 1:1 to 1:6, morepreferably 1:2 to 1:5.

The contacting is generally effected at a temperature of 20 to 200° C.,preferably 50 to 150° C., more preferably 60 to 150° C.

The reaction time depends on the desired carbene complex and isgenerally 0.02 to 50 hours, preferably 0.1 to 24 hours, more preferably1 to 24 hours.

The metal carbene complexes comprising at least one ligand of formula(A), preferably of formula (I) obtained after the reaction canoptionally be purified by processes known to those skilled in the art,for example washing, crystallization or chromatography, and optionallyisomerized under conditions likewise known to those skilled in the art,for example with acid mediation, thermally or photochemically.

Suitable processes for preparing the metal carbene complex comprising atleast one ligand of formula (A), preferably of formula (I) are forexample mentioned in WO 2011/073149 and EP13174779.

The resulting complexes may yield different isomers that can beseparated or converted into a form with a major isomer by isomerizationof the mixture.

(b) Post Functionalization

It is also possible to insert the radical R⁵—if present—bypost-functionalization of the metal carbene complex (which does notcomprise a residue R⁵). In the case of inventive heteroleptic metalcarbene complexes comprising a ligand L selected from the ligands (X-1),(X-2), (X-3) or (X-4), comprising a substitutable position R⁵ (theposition R⁵ is shown in the ligands (X-1′), (X-2′), (X-3′) or (X-4′)),in general, also the position R⁵ in said ligand L is post-functionalizedat the same time.

The post-functionalization is exemplified in the following for ligandsof formula (I), wherein Z—as mentioned in the ligands of formula (A)—isNR^(x). However, a person skilled in the art knows that thepost-functionalization steps can be easily transferred to prepareligands of formula (A), wherein Z is O or S.

The present invention therefore further provides a process for preparinga metal carbene complex according to the present invention, comprisingat least one ligand of formula (I′)

wherein the residues R¹, R², R³, R⁴, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ havebeen defined before, andR^(5′) is a C₁-C₁₈alkyl group, which can optionally be substituted by atleast one substituent E and/or interrupted by D; a C₃-C₁₂cycloalkylgroup, which can optionally be substituted by at least one substituentE; a C₆-C₁₄aryl group, which can optionally be substituted by at leastone substituent G; a —N(C₆-C₁₄aryl)₂ group, which can optionally besubstituted by at least one substituent G; or a heteroaryl groupcomprising 3 to 11 ring atoms, which can optionally be substituted by atleast one substituent G, interrupted by at least one of O, S and N;comprising reacting metal carbene complex, wherein the metal is selectedfrom Ir and Pt, comprising at least one ligand of formula of formula(III)

with a compound of formula (IV) corresponding to the respectiveY-substituted residue R^(5′):R^(5′)—Y (IV)whereinX¹ is Cl, Br, or I, especially Br;Y is —B(OH)₂, —B(OY¹)₂,

wherein Y¹ is a C₁-C₁₀alkyl group and Y² is independently in eachoccurrence a C₂-C₁₀alkylene group, such as —CY³Y⁴—CY⁵Y⁶—, or—CY⁷Y⁸—CY⁹Y¹⁰—CY¹¹Y¹²—, wherein Y³, Y⁴, Y⁵, Y⁶, Y⁷, Y⁸, Y⁹, Y¹⁰, Y¹¹ andY¹² are independently of each other hydrogen, or a C₁-C₁₀alkyl group,especially —C(CH₃)₂C(CH₃)₂—, —CH₂C(CH₃)₂CH₂—, or —C(CH₃)₂CH₂C(CH₃)₂—,and Y¹³ and Y¹⁴ are independently of each other hydrogen, or aC₁-C₁₀alkyl group;—SnR³⁰⁷R³⁰⁸R³⁰⁹, wherein R³⁰⁷, R³⁰⁸ and R³⁰⁹ are identical or differentand are H or C₁-C₆alkyl, wherein two radicals optionally form a commonring and these radicals are optionally branched or unbranched;ZnR³¹⁰R³¹¹, wherein R³¹⁰ is halogen and R³¹¹ is a C₁-C₁₀alkyl group, aC₆-C₁₂aryl group, or C₁-C₁₀alkenyl group; orSiR³¹²R³¹³R³¹⁴, wherein R³¹², R³¹³ and R³¹⁴ are identical or differentand are halogen, or C₁-C₆alkyl.

Preferred residues R^(5′) are:

a C₁-C₁₂alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by E;

or

R^(5′), is a group of formula

R^(a) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably H, a C₁-C₅alkyl group, C₃-C₆cycloalkylgroup; more preferably H, or a C₁-C₅alkyl group;R^(e) is H, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group, or aC₃-C₆cycloalkyl group; preferably H, a C₁-C₅alkyl group, C₃-C₆cycloalkylgroup; more preferably H, or a C₁-C₅alkyl group;R^(c), R^(b) and R^(d) are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by G; a C₆-C₁₄aryl group, which can optionally besubstituted by G; or a C₂-C₃₀heteroaryl group, which can optionally besubstituted by G; C₁-C₈haloalkyl such as CF₃; orSiR⁸⁰R⁸¹R⁸²; preferably R^(c), R^(b) and R^(d) are independently of eachother H, a C₁-C₅alkyl group, C₃-C₆cycloalkyl group; more preferably H,or a C₁-C₅alkyl group;orR^(c) and R^(b), or R^(a) and R^(b) together form a group of formula

wherein X is O, S, NR⁷⁵ or CR⁷³R⁷⁴; R′″ is C₁-C₈alkyl and a is 0, 1 or2, preferably 0 or 1, more preferably 0.

More preferably, R^(5′) is a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent E and/or interrupted by D; orR^(5′) is a C₃-C₆cycloalkyl group, which can optionally be substitutedby at least one substituent E; or a phenyl group, which can optionallybe substituted by one or two groups G.

Most preferably, R^(5′) is a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent E; or a C₃-C₆cycloalkyl group,which can optionally be substituted by at least one substituent E; or aphenyl group, which can optionally be substituted by one or two groupsG.

Suitable and preferred groups E, D and G are mentioned before.

Preferred residues R¹, R², R³, R⁴, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁸ have alsobeen defined before.

Preferred reactions for the introduction of the substituent R^(5′) onthe compound of formula (III) are in general metal catalyzed reactionsand more specifically Suzuki, Ullmann, Negishi, Heck, Stille and Kumadacoupling reactions (J. Hassan et al., Chemical Reviews 102 (2002) 5; L.Ackermann: “Modern Arylation Methods” (Ed.: L. Ackermann), Wiley-VCH,Weinheim, 2009).

Preferably, the inventive metal carbene complex of formula (I′)comprising a residue R^(5′) as mentioned above can be synthesized by oneof the following coupling reactions:

i) Negishi coupling reaction using a compound of formula: R^(5′)—Y,wherein Y is ZnR³¹⁰R³¹¹, wherein R³¹⁰ is halogen and R³¹¹ is aC₁-C₁₀alkyl group, a C₆-C₁₂aryl group, or C₁-C₁₀alkenyl group. Referenceis, for example, made to B. Vilas et al., Chem. Soc. Rev., 38 (2009)1598-1607.ii) Stille coupling reaction using a compound of formula: R^(5′)—Y,wherein Y is —SnR³⁰⁷R³⁰⁸ R³⁰⁹, wherein R³⁰⁷, R³⁰⁸ and R³⁰⁹ are identicalor different and are H or C₁-C₆alkyl, wherein two radicals optionallyform a common ring and these radicals are optionally branched orunbranched. Reference is, for example, made to J. K. Stille, Angew.Chem. 98 (1986) 504-519; P. Espinet et al., Angew. Chem. Int. Ed., 43(2004) 4704-4734.iii) Hiyama coupling reaction using a a compound of formula: R^(5′)—Y,wherein Y is SiR³¹²R³¹³R³¹⁴, wherein R³¹², R³¹³ and R³¹⁴ are identicalor different and are halogen, or C₁-C₆alkyl. Reference is, for example,made to T. Hiyama et al., Pure Appl. Chem. 66 (1994) 1471-1478 and T.Hiyama et al., Synlett (1991) 845-853.iv) Suzuki coupling reaction using a a compound of formula: R^(5′)—Y,wherein Y is —B(OH)₂, —B(OY¹)₂,

wherein Y¹ is a C₁-C₁₀alkyl group and Y² is independently in eachoccurrence a C₂-C₁₀alkylene group, such as —CY³Y⁴—CY⁵Y⁶—, or—CY⁷Y⁸—CY⁹Y¹⁰—CY¹¹Y¹²—, wherein Y³, Y⁴, Y⁵, Y⁶, Y⁷, Y⁸, Y⁹, Y¹⁰, Y¹¹ andY¹² are independently of each other hydrogen, or a C₁-C₁₀alkyl group,especially —C(CH₃)₂C(CH₃)₂—, —CH₂C(CH₃)₂CH₂—, or —C(CH₃)₂CH₂C(CH₃)₂—,and Y¹³ and Y¹⁴ are independently of each other hydrogen, or aC₁-C₁₀alkyl group. Reference is, for example, made to A. Suzuki et al.,Chemical Reviews 95 (1995) 2457-2483, “Suzuki in Modern Arene Chemistry”(Ed.: D. Astruc), Wiley-VCH, Weinheim, 2002, pp. 53-106. More preferablySuzuki and Negishi coupling reactions are used. Suzuki type reactionsare most preferred.

Preferably, the Suzuki reaction of compound (III) with compound (IV) iscarried out in presence of

a) a catalyst/ligand system comprising a palladium catalyst and anorganic phosphine or phosphonium compound,

b) a base,

c) a solvent or a mixture of solvents.

The organic solvent is usually an aromatic hydrocarbon, a linear,branched, or cyclic ether, or a usual polar organic solvent, such asbenzene, toluene, xylene, tetrahydrofurane, or dioxane, or mixturesthereof. If desired, water can be added to the organic reaction medium,in which case, depending on the organic solvent used, the reaction canbe carried out in a single phase or in a two-phase mixture.

Usually, the amount of the solvent is chosen in the range of from 1 to10 l per mol of boronic acid derivative.

Also preferred, the reaction is carried out under an inert atmospheresuch as nitrogen, or argon.

Further, it is preferred to carry out the reaction in the presence of anaqueous base, such as an alkali metal hydroxide, metal phosphate, orcarbonate such as NaOH, KOH, K₃PO₄, Na₂CO₃, K₂CO₃, or Cs₂CO₃.

Organic bases, such as, for example, tetraalkylammonium hydroxide, andphase transfer catalysts, such as, for example TBAB, can promote theactivity of the boron (see, for example, Leadbeater & Marco; Angew.Chem. Int. Ed. Eng. 42 (2003) 1407 and references cited therein).

Usually, the molar ratio of the base to boronic acid or boronic esterderivative is chosen in the range of from 0.5:1 to 50:1, very especiallyin the range of 1:1 to 5:1.

Generally, the reaction temperature is chosen in the range of from 40 to180° C., preferably under reflux conditions.

Generally, the reaction time is chosen in the range of from 0.5 to 80hours, preferably from 2 hours to 60 hours.

In a preferred embodiment a usual catalyst for coupling reactions or forpolycondensation reactions is used, preferably Pd-based, which isdescribed in WO2007/101820. The palladium compound is added in a ratioof from 1:10000 to 1:50, preferably from 1:5000 to 1:200, based on thenumber of bonds to be closed. Preference is given, for example, to theuse of palladium(II) salts such as PdOAc₂ or Pd₂dba₃ and to the additionof ligands selected from the group consisting of

wherein

The ligand is added in a ratio of from 1:1 to 1:10, based on Pd. Alsopreferred, the catalyst is added as in solution or suspension.Preferably, an appropriate organic solvent such as the ones describedabove, preferably benzene, toluene, xylene, THF, dioxane, morepreferably toluene, or mixtures thereof, is used. The amount of solventusually is chosen in the range of from 1 to 10 l per mol of boronic acidderivative.

Other variations of reaction conditions are given by T. I. Wallow and B.M. Novak in J. Org. Chem. 59 (1994) 5034-5037; and M. Remmers, M.Schulze, G. Wegner in Macromol. Rapid Commun. 17 (1996) 239-252 and G.A. Molander und B. Canturk, Angew. Chem., 121 (2009) 9404-9425.

The following reaction systems are preferred:

i) aryl boronic acid, tris(dibenzylideneacetone) dipalladium(0), SPhos(Dicyclohexylphosphino-2′,6′-dimethoxybiphenyl), tripotassium phosphate(solvent toluene/water mixture);

ii) aryl boronic acid, bis(tri-t-butylphosphin)palladium(0)(Pd[P(tBu)₃]₂), sodium hydroxide (solvent toluene/dioxane/watermixture); and

iii) aryl boronic acid, palladium acetate (Pd(OAc)₂), SPhos(Dicyclohexylphosphino-2′,6′-dimethoxybiphenyl), tripotassium phosphate(o-xylene mixture).

The metal carbene complex, wherein the metal is selected from Ir and Pt,comprising at least one ligand of formula of formula (III) can beobtained by reacting a metal carbene complex,

wherein the metal is selected from Ir and Pt, comprising at least oneligand of formula of formula

with a halogenating agent, wherein R¹, R², R³, R⁴, R⁶, R⁷, R⁸, R⁹, R²⁷and R²⁸ have been defined before. The halogenation can be performed bymethods known to those skilled in the art.

Halogenating agents according to the invention are the halogens X₂ orthe interhalogens X—X and a base in a ratio of from 1:1 to 1:100 andoptionally a Lewis acid in a ratio (halogen to Lewis acid) of from 1:0.1to 1:0.0001, for example chlorine, bromine or iodine, or chlorinefluoride, bromine fluoride, iodine fluoride, bromine chloride, iodinechloride or iodine bromide, in combination with organic bases such asamines, for example triethylamine, tri-n-butylamine,diisopropylethylamine, morpholine, N-methylmorpholine and pyridine, orsalts of carboxylic acids such as sodium acetate, sodium propionate,sodium benzoate, or inorganic bases such as sodium or potassiumphosphate or hydrogenphosphate, potassium or sodium hydrogencarbonate,potassium or sodium carbonate, or else organic bromine complexes such aspyridinium perbromide, optionally each in combination with a Lewis acid,e.g. boron trifluoride, boron trifluoride etherate, boron trichloride,boron tribromide, boron triiodide, aluminum trichloride, aluminumtribromide, aluminum triiodide, iron(III) chloride, iron(III)bromide,zinc(II)chloride, zinc(II)bromide, tin(IV)chloride, tin(IV)bromide,phosphorus pentachloride, arsenic pentachloride and antimonypentachloride are used.

Further halogenating agents according to the invention are organic N—Xcompounds, such as1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octanebis(tetrafluoroborate), or N-halocarboxamides such as N-chloro-,N-bromo- and N-iodoacetamide, N-chloro-, N-bromo- andN-iodopropionamide, N-chloro-, N-bromo- and N-iodobenzamide, orN-halocarboximides such as N-chloro-, N-bromo- and N-iodosuccinimide,N-chloro-, N-bromo- and N-iodophthalimide, or N,N-dihalohydantoins, suchas 1,3-dibromo-5,5-dimethylhydantoin,1,3-dichloro-5,5-dimethylhydantoin, 1,3-diiodo-5,5-dimethylhydantoin orN-dihalosulfonamides such as, benzenesulfo-N-dibromamide, orN-halosulfonamide salts such as chloramine B or T. In the case of thesehalogenating agents, the additive use of Lewis acids, as listed above,for example, may likewise be advantageous.

Preferred halogenating agents N-halocarboxamides such as N-chloro-,N-bromo- and N-iodosuccinimide, N-chloro-, N-bromo- andN-iodophthalimide, or N,N-dihalohydantoins, such as1,3-dibromo-5,5-dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoinand 1,3-diiodo-5,5-dimethylhydantoin.

In the process according to the invention, a stoichiometric ratio or anexcess of the halogenating agent based on the content of active halogen,to the ligands (III′) is used, and can lead selectively to the ligands(III). Preferably a stoichiometric ratio up to a ratio of 2:1 of thehalogenating agent based on the content of active halogen to the ligands(III′) is used. More preferably a stoichiometric ratio is used.

Reaction media according to the invention are protic or aprotic,halogen-free or halogenated solvents, for example alcohols such asmethanol, ethanol, propanol, butanol, polyhydric alcohols such asethylene glycol, propyleneglycol, nitriles such as acetonitrile,propionitrile or benzonitrile, ethers such as diethyl ether THF ordioxane, aromatic hydrocarbons such as benzonitrile, nitrobenzene orchlorobenzene, N,N-dialkylamides such as dimethylformamide,methylacetamide or N-methylpyrroldinone, sulfoxides, such as dimethylsulfoxide, sulfones such as dimethylsulfone or sulfolane, halogenatedhydrocarbons such as dichloromethane, trichloromethanen,1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane.Preference is given to aromatic or chlorinated solvents.

According to the invention, the concentration of the metal carbenecomplex comprising at least one ligand of formula (III′) is in the rangefrom 0.0005 mol/l to 2 mol/l, more preferably in the range from 0.002mol/l to 0.1 mol/l.

According to the invention, the metal carbene complex comprising atleast one ligand of formula (III′) may be dissolved or suspended in thereaction medium.

According to the invention, the reaction is carried out in thetemperature range from −78° C. to 150° C., preferably at from 0° C. to80° C., more preferably at from 0° C. to 40° C.

According to the invention, the reaction is carried out within from 1 hto 100 hours, preferably within from 3 h to 60 h.

Brominating in the 3 position of the cyclometallating N-aryl group ofthe imidazo-quinoxaline carbene ligand can be, for example, accomplishedby reaction of the metal carbene complex comprising at least one ligandof formula (III′) with N-bromosuccinimide in dichloromethane.

Iodinating in the 3 position of the cyclometallating N-aryl group of theimidazo-quinoxaline carbene ligand can be, for example, accomplished byreaction of the metal carbene complex comprising at least one ligand offormula (III′) with N-iodosuccinimide in dichloromethane.

(c) Preparation of Imidazo-Quinoxaline Carbene Ligands

The imidazo-quinoxalines which form the basis for theimidazo-quinoxaline carbene ligands in the metal carbene complexes ofthe present invention are commercially available or prepared by methodsknown in the art and for example described in Saravanakumar et al.,Chem. Commun. 2006, 640-642; Al-Raqa et al., Heteroatom Chem. 17:634-647, 2006; El-Sharief et al., Heteroatom Chem. 16: 218-225, 2005;Phukan et al., J. Org. Chem. 2013, 78, 11032-11039; JP-A 2000-121807;and Semenov et al., Russian Journal of Organic Chemistry, 2010, Vol. 46,No. 3, pp. 439-443.

Exemplary examples for the preparation of inidazo-quinoxaline ligandsare shown in the experimental part of the present application.

Organic Electronic Devices

The inventive metal carbene complexes can be used in organic electronicdevices. Suitable organic electronic devices are selected from organiclight-emitting diodes (OLEDs), organic photovoltaic cells (OPVs),organic field-effect transistors (OFETs) and light-emittingelectrochemical cells (LEECs), preference being given to OLEDs.

The inventive metal carbene complexes are generally notable for improveddevice performance such as high external quantum efficiency, highluminous efficacy and low voltage, green to yellow emission, decreasedlifetime of the luminescence τ (higher radiation rate k_(rad)), reducedcolor-shift (e.g. CIE-y shift) with increasing doping concentration, orlong device lifetime and/or excellent thermal stability. The inventivemetal-carbene complexes are therefore suitable with particularpreference as emitter material in OLEDs

The present invention therefore concerns an organic electronic device,comprising at least one metal carbene complex according to the presentinvention.

In a preferred embodiment, the organic electronic device is an OLED. Thepresent application therefore further provides an OLED comprising atleast one inventive metal carbene complex. The inventive metal carbenecomplex is used in the OLED preferably as an emitter, matrix material,charge transport material, especially hole transport material, and/orcharge blocker, more preferably as an emitter and/or hole transportmaterial, most preferably as emitter.

In a further embodiment, the inventive metal carbene complex is used inthe OLED as an electron transport material or as an electron transportmaterial and a hole transport material.

The present application also provides for the use of the inventive metalcarbene complexes in OLEDs, preferably as emitter, matrix material,charge transport material, especially hole transport material, and/orcharge blocker, more preferably as emitter and/or hole transportmaterial, most preferably as emitter.

The at least one inventive metal carbene complex is more preferablypresent in the light-emitting layer of an OLED, most preferably asemitter. The present application therefore also provides for alight-emitting layer comprising at least one inventive metal carbenecomplex, preferably as emitter. More preferably, the light-emittinglayer additionally comprises at least one host material. Mostpreferably, the light-emitting layer additionally comprises two hostmaterials.

In a further embodiment, the present invention relates to alight-emitting layer consisting of at least one inventive metal carbenecomplex.

Organic light-emitting diodes are in principle formed from a pluralityof layers, e.g.:

(a) an anode,

(b) optionally a hole injection layer,

(c) optionally a hole transport layer,

(d) optionally an electron/exciton blocking layer

(e) a light-emitting layer,

(f) optionally a hole/exciton blocking layer,

(g) optionally an electron transport layer,

(h) optionally an electron injection layer, and

(i) a cathode.

It is, however, also possible that the OLED does not comprise all of thelayers mentioned; for example, an OLED comprising layers (a) (anode),(e) (light-emitting layer) and (i) (cathode) is likewise suitable, inwhich case the functions of layers (c) (hole-transport layer) and (g)(electron-transport layer) are assumed by the adjoining layers. OLEDscomprising layers (a), (c), (e), (g) and (i) or (a), (c), (e) and (i) orlayers (a), (e), (g) and (i) or (a), (b), (c), (d), (e), (g), (h) and(i) or (a), (b), (c), (e), (g), (h) and (i) or (a), (b), (c), (d), (e),(g) and (i) are likewise suitable.

The individual layers among the aforementioned layers of the OLED may inturn be formed from two or more layers. For example, the hole-transportlayer may be formed from one layer, into which holes are injected fromthe electrode, and a layer which transports the holes away from thehole-injecting layer into the light-emitting layer. Theelectron-transport layer may likewise consist of a plurality of layers,for example of a layer in which electrons are injected through theelectrode and a layer which receives electrons from theelectron-injecting layer and transports them into the light-emittinglayer. These layers mentioned are each selected according to factorssuch as energy level, thermal resistance and charge carrier mobility,and also energy difference of the layers mentioned with the organiclayers or the metal electrodes. The person skilled in the art is capableof selecting the construction of the OLEDs such that it is matchedoptimally to the inventive metal-carbene complexes, preferably used asemitter substances in accordance with the invention.

In order to obtain particularly efficient OLEDs, the HOMO (highestoccupied molecular orbital) of the hole-transport layer should bealigned to the work function of the anode, and the LUMO (lowestunoccupied molecular orbital) of the electron-transport layer should bealigned to the work function of the cathode.

Suitable materials for the aforementioned layers (anode, cathode, holeand electron injection materials, hole and electron transport materialsand hole and electron blocker materials, matrix materials, fluorescenceand phosphorescence emitters) are known to those skilled in the art andare specified, for example, in H. Meng, N. Herron, Organic SmallMolecule Materials for Organic Light-Emitting Devices in OrganicLight-Emitting Materials and Devices, eds: Z. Li, H. Meng, Taylor &Francis, 2007, Chapter 3, pages 295 to 411 as well as in US2012/0104422,D. J. Gaspar, E Polikarpov, OLED Fundamentals: Materials, Devices, andProcessing of Organic Light-Emitting Diodes, CRC Press, Taylor &Francis, 2015, and Z. R. Li, Organic Light-Emitting Materials andDevices, CRC Press, Taylor & Francis, 2015.

In addition, it is possible that some or all of the layers (b) to (h)have been surface-treated in order to increase the efficiency of chargecarrier transport. The selection of the materials for each of the layersmentioned is preferably determined by obtaining an OLED having a highefficiency.

The inventive metal carbene complexes are preferably used as emittermolecules and/or matrix materials in the light-emitting layer (e). Theinventive metal-carbene complexes may—in addition to use as emittermolecules and/or matrix materials in the light-emitting layer (e) orinstead of use in the light-emitting layer—also be used as a chargetransport material in the hole-transport layer (c) or in theelectron-transport layer (g) and/or as a charge blocker, preferencebeing given to use as a charge transport material in the hole-transportlayer (c) (hole transport material).

In a further embodiment, the inventive metal carbene complex is used asan electron transport material, or as an electron transport material anda hole transport material.

Light-Emitting Layer (e)

Emitter

Suitable emitter materials for OLEDs are known by a person skilled inthe art. The light-emitting layer preferably comprises at least onephosphorescent emitter. Phosphorescent emitter are preferred because ofthe higher luminescent efficiencies associated with such materials. Thelight-emitting layer preferably also comprises at least one hostmaterial. Preferably, the host material is capable of transportingelectrons and/or holes, doped with an emitting material that may trapelectrons, holes, and/or excitons, such that excitons relax from theemissive material via a photoemissive mechanism. In a preferredembodiment, the light emitting layer comprises the emitter and two hostmaterials. In this case the two host materials both contribute to thetransport of electrons and/or holes. By adjusting the mixing ratio ofthe two host materials, the optimal charge carrier balance and thus theoptimal device performance in terms of voltage, lifetime, efficiencyand/or color can be achieved.

It is an object of the present invention to provide organic electronicdevices, preferably OLEDs, having—compared with the organic electronicdevices known in the art—a high color purity in the green to yellowregion of the visible electromagnetic spectrum, a high efficiency, lowvoltage and/or improved lifetime/stability to provide organic electronicdevices, preferably OLEDs, having—compared with the organic electronicdevices known in the art—a high color purity in the green to yellowregion of the visible electromagnetic spectrum, a high efficiency, lowvoltage and/or improved lifetime/stability.

The emitter in the OLED of the present invention is therefore preferablya phosphorescent emitter emitting light in the green to yellow region ofthe visible electromagnetic spectrum (“phosphorescent green emitter”).

The term “phosphorescent green emitter” as used herein refers to ayellow or green phosphorescent emitter having an emission maximum(λ_(max)), which is located at 510 nm to 590 nm, preferably at 515 nm to570 nm.

Suitable phosphorescent green emitters are known in the prior art, forexample in Baldo et al., Applied Physics Letters, vol. 75, No. 1, 5 Jul.1999, 4-6, US 2011/0227049 A1, US 2014/0203268 A1, US 2013/0341609, US2013/0181190, US 2013/0119354, WO 2012/053627 A1, and WO 2013/112557,

Preferably, the inventive metal carbene complexes are used as emitter.The light-emitting layer (e) may comprise one or more of the inventivemetal-carbene complexes as emitter material. Suitable and preferredinventive metal carbene complexes are mentioned above. It is alsopossible that the light-emitting layer comprises in addition to at leastone inventive metal carbene complex one or more further emitters.

The light-emitting layer preferably comprises beside at least oneemitter material (suitable emitter materials are mentioned above),preferably at least one metal carbene complex according to the presentinvention, at least one host material.

Suitable host materials are known by a person skilled in the art.Preferred host materials are mentioned below.

Host

For efficient light emission the triplet energy of the host material hasto be about 0.2 eV larger than the triplet energy of the phosphorescentemitter (preferably the metal carbene complex according to the presentinvention) used. Hence, all host materials fulfilling this requirementare, in principle, suitable as host compound.

Suitable host materials for phosphorescent green to yellow emitters are,for example, described in EP2363398A1, WO2008/031743, WO2008/065975,WO2010/145991, WO2010/047707, US2009/0283757, US2009/0322217,US2010/0001638, WO2010/002850, US2010/0060154, US2010/0060155,US2010/0076201, US2010/0096981, US2010/0156957, US2011/186825,US2011/198574, US2011/0210316, US2011/215714, US2011/284835, andWO2012/045710. Further suitable host materials for phosphorescent greento yellow emitters are, for example, described in WO2012/004765 andUS2011/0006670 (e.g. SH-2 Host), US2014/0001446 and WO2015/014791. Thehost material may be a compound having hole-transporting property and/oran organic compound having electron-transporting property. Preferably,the host material is an organic compound or organometallic compoundhaving hole-transporting property. Alternatively the host compound maybe a mixture of an organic compound or organometallic compound havinghole-transporting property and an organic compound or organometalliccompound having electron-transporting property. In principle, anyorganic compound or organometallic compound having hole-transportingproperty or having electron-transporting property and sufficient tripletenergy can be used as host in the light-emitting layer. In a preferredembodiment, it is also possible to combine an organic compound ororganometallic compound having both hole- and electron-transportingproperty and an organic compound or organometallic compound havingeither hole- or electron-transporting properties as hosts. Bothmaterials can be processed from separate sources or as one pre-mixedhost-compound.

Examples of organic compounds which can be used for the host materialinclude a carbazole derivative such as 4, 4′-di(carbazolyl)biphenyl(abbreviation: CBP), 1,3-bis(carbazolyl)benzene (abbreviation: mCP) or1,3,5-tris(N-carbazolyl)benzene (abbreviation: TCzB), =DNTPD.

Examples of organometallic compounds which can be used for the hostmaterial include iridium carbene complexes. Suitable iridium carbenecomplexes are, for example, iridium carbene complexes as described inWO2005/019373A2, WO2006/056418 A2, WO2007/115970, WO2007/115981,WO2008/000727, WO2012/121936A2, US2012/0305894A1, and WO2012/172482A1.Examples of suitable iridium carbene complexes are Ir(DPBIC)₃ with theformula:

(HTM-1) and Ir(ABIC)₃ with the formula:

(HTM-2).

Further suitable host materials are the compounds described inWO2010/079051 (in particular pages on 19 to 26 and in the tables onpages 27 to 34, pages 35 to 37 and pages 42 to 43).

Also preferred as host compounds in the OLED and in the light-emittinglayer of the present invention are the compounds mentioned inWO2012/130709; WO2013/050401; WO2014/009317; WO2014/044722; and thenon-published European Patent Application EP13191100.0.

Further preferred host materials are binary host systems as described inWO2011/136755; the hosts described in WO2013/022419 and WO2013/112557;triphenylene derivatives for example as described in WO2010/028151,WO2010/002850, WO2010/0056669, US2010/0244004, US2011/0177641,US2011/022749, WO2011/109042, and WO2011/137157; azaborinine compoundsfor example as described in WO2011/143563; bicarbazole compounds forexample as described in WO2012/023947; carbazolephenyl-pyridine,-pyrimidine and -triazine compounds for example as described inWO2012/108879; biscarbazolephenyl-pyridine, -pyrimidine and -triazinecompounds for example as described in WO2012/108881; dibenzoquinoxalinecompounds for example as described in US2011/0210316; triazolederivatives for example as described in US2011/0285276 andUS2012/0025697; benzimidazole derivatives for example as described inUS2011/0147792; heterocyclic compounds for example as described inUS2012/0061651; phenanthrene derivatives for example as described inUS2012/0104369; benzoxazole derivatives for example as described inUS2012/0132896; oxazole derivatives for example as described inUS2012/0130081; and carbazole-benzimidazole derivatives for example asdescribed in US2012/0133274.

Further preferred host materials are described in US2011/0006670 (theSH-2 host is for example mentioned therein).

Especially suitable host materials are for example host materialsdescribed in WO2013/112557 having the following general formula:

wherein R¹, R², R3, R⁴, R⁵, and R⁶ may be the same or different fluorineatom, chlorine atom, a deuterium atom, a cyano group, a trifluoromethylgroup, a nitro group, linear or branched C₁-C₆alkyl group,C₅-C₁₀cyclo-alkyl group, linear or branched C₁-C₆alkoxy group,C₅-C₁₀cyclo-alkoxy group, substituted or unsubstituted aromatichydrocarbon group, substituted or unsubstituted aromatic heterocyclicgroup, substituted or unsubstituted condensed polycyclic aromatic group,r1, r4, r5 is 0, 1, 2, 3, or 4,r2, r3, r6 is 0, 1, 2 or 3,n is 0 or 1, andAr¹, Ar², and Ar³ may be the same or different, substituted orunsubstituted aromatic hydrocarbon group, substituted or unsubstitutedaromatic heterocyclic group, substituted or unsubstituted condensedpolycyclic aromatic group, deuterium substituted aromatic hydrocarbongroup, deuterium substituted aromatic heterocyclic group, or deuteriumsubstituted condensed polycyclic aromatic group.

When Ar¹, Ar2, or Ar³ is a substituted aromatic hydrocarbon group, asubstituted aromatic heterocyclic group, or a substituted polycyclicaromatic group, the substitution groups can be any non-carbon orcarbon-containing functional group, such as, an aromatic hydrocarbongroup, an aromatic heterocyclic group or a polycyclic aromatic group.For example, the substitution group on the aromatic ring structure ofAr¹, A², or Ar³ can be

or the like.

Especially suitable are the compounds (H1-1), (H1-2), (H1-7) asmentioned below and the compounds (H1-3), (H1-4), (H1-5), (H1-6),(H1-8), (H1-9), (H1-10), (H1-11), (H1-12), (H1-13), (H1-14), (H1-14),(H-16) and (H1-17) as described in WO 2013/112557.

Further suitable host materials—which may be employed together with thehost material mentioned before—are host materials containing at leastone of the following groups in the molecule:

wherein X¹ to X⁸ is selected from C or N; and wherein Z¹ and Z² is S orO.

The groups mentioned above may be unsubstituted or substituted by anunfused substituent independently selected from the group consisting ofC_(n)H_(2n+1), OC_(n)H_(2n+1), OAr₁, N(C_(n)H_(2n+1))₂, N(Ar₁)(Ar₂),CH═CH—C_(n)H_(2n+1), C═CHC_(n)H_(2n+1), A₁, Ar₁-Ar₂, C_(n)H_(2n−Ar1),wherein n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and wherein Ar₁ and Ar₂are independently selected from the group consisting of benzene,biphenyl, naphthalene, triphenylene, carbazole, and heteroaromaticanalogs thereof.

Further suitable host compounds are compounds comprising a triphenylenecontaining benzo-fused thiophene. A combination of benzo-fusedthiophenes and triphenylene as hosts in OLEDs may be beneficial.Therefore combining these two moieties in one molecule may offerimproved charge balance which may improve device performance in terms oflifetime, efficiency and low voltage. Different chemical linkage of thetwo moieties can be used to tune the properties of the resultingcompound to make it the most appropriate for a particular phosphorescentemitter, device architecture, and/or fabrication process. For example,m-phenylene linkage is expected to result in higher triplet energy andhigher solubility whereas p-phenylene linkage is expected to result inlower triplet energy and lower solubility.

Similar to the characterization of benzo-fused thiophenes, benzo-fusedfurans are also suitable host materials. Examples of benzo-fused furansinclude benzofuran and dibenzofuran. Therefore, a material containingboth triphenylene and benzofuran may be advantageously used as hostmaterial in OLEDs. A compound containing both of these two groups mayoffer improved electron stabilization which may improve device stabilityand efficiency with low voltage. The properties of the triphenylenecontaining benzofuran compounds may be tuned as necessary by usingdifferent chemical linkages to link the triphenylene and the benzofuran.

Benzo-fused furans are benzofurans and dibenzofurans. Benzo-fusedthiophenes are benzothiophenes and dibenzothiophenes.

The benzo-fused thiophene and benzo-fused furans mentioned above may beunsubstituted or substituted for example by one or more unfusedsubstituents independently selected from the group consisting ofC_(n)H_(2n+1), OC_(n)H_(2n+1), OAr₁, N(C_(n)H_(2n+1))₂, N(Ar₁)(Ar₂),CH═CH—C_(n)H_(2n+1), C═CHC_(n)H_(2n+1), A₁, Ar₁-Ar₂, C_(n)H_(2n−Ar1),wherein n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and wherein Ar₁ and Ar₂are independently selected from the group consisting of benzene,biphenyl, naphthalene, triphenylene, carbazole, and heteroaromaticanalogs thereof.

The substituents of the compounds described above are unfused such thatthe substituents are not fused to the triphenylene, benzo-fused furan orbenzo-fused thiophene moieties of the compound. The substituents mayoptionally be inter-fused (i.e. fused to each other).

The benzo-fused thiophene and benzo-fused furans mentioned above are forexample described in WO2013/112557 and in WO2009/021126.

Further suitable host materials for phosphorescent green emitters arementioned in US2013/0181190, especially in table 3, and US2013/0119354,especially in table 4.

Specific examples of organic compounds which can be used for the hostmaterial include a compounds such as

wherein Z³ is O or S and p is 0 or 1, such as

Further specific examples of organic compounds which can be used for thehost material include the following compounds

The host compound can be one compound or it can be a mixture of two ormore compounds. Suitable mixtures are for example the binary hostssystems as described in WO2011/136755 and WO2013/112557.

A further suitable host material for the emitters of the presentinvention is mentioned in US2012/0235123 and US2011/0279020. A typicaland preferred host material described in the documents mentioned beforeis

Additionally, as mentioned before, co-host systems are suitable as hostmaterial for the emitters of the present invention. A suitable co-hostsystem is exemplified below. It is clear for a person skilled in the artthat also similar co-host systems are suitable.

combined with

In a preferred embodiment, the light-emitting layer (e) comprises theemitter in an amount of 2 to 40% by weight, preferably 5 to 35% byweight, more preferably 5 to 20% by weight and the host compound in anamount of 60 to 98% by weight, preferably 65 to 95% by weight, morepreferably 80 to 95% by weight, where the amount of the phosphorescentemitter and the host compound adds up to a total of 100% by weight. Theemitter may be one emitter or a combination of two ore more emitters.The host may be one host or a combination of two or more hosts. In apreferred embodiment, in case of the use of two host compounds they aremixed in a ratio of 1:1 to 1:30, more preferably 1:1 to 1:7, mostpreferably 1:1 to 1:3.

Anode (a)

The anode is an electrode which provides positive charge carriers. Itmay be composed, for example, of materials which comprise a metal, amixture of different metals, a metal alloy, a metal oxide or a mixtureof different metal oxides. Alternatively, the anode may be a conductivepolymer. Suitable metals comprise the metals of groups 11, 4, 5 and 6 ofthe Periodic Table of the Elements, and also the transition metals ofgroups 8 to 10. When the anode is to be transparent, mixed metal oxidesof groups 12, 13 and 14 of the Periodic Table of the Elements aregenerally used, for example indium tin oxide (ITO). It is likewisepossible that the anode (a) comprises an organic material, for examplepolyaniline, as described, for example, in Nature, Vol. 357, pages 477to 479 (Jun. 11, 1992). Preferred anode materials include conductivemetal oxides, such as indium tin oxide (ITO) and indium zinc oxide(IZO), aluminum zinc oxide (AlZnO), and metals. Anode (and substrate)may be sufficiently transparent to create a bottom-emitting device. Apreferred transparent substrate and anode combination is commerciallyavailable ITO (anode) deposited on glass or plastic (substrate). Areflective anode may be preferred for some top-emitting devices, toincrease the amount of light emitted from the top of the device. Atleast either the anode or the cathode should be at least partlytransparent in order to be able to emit the light formed. Other anodematerials and structures may be used.

Hole Injection Layer (b)

Generally, injection layers are comprised of a material that may improvethe injection of charge carriers from one layer, such as an electrode ora charge generating layer, into an adjacent organic layer. Injectionlayers may also perform a charge transport function. The hole injectionlayer may be any layer that improves the injection of holes from anodeinto an adjacent organic layer. A hole injection layer may comprise asolution deposited material, such as a spin-coated polymer, or it may bea vapor deposited small molecule material, such as, for example, CuPc orMTDATA. Polymeric hole-injection materials can be used such aspoly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole, polyaniline,self-doping polymers, such as, for example, sulfonatedpoly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl) (Plexcore® OCConducting Inks commercially available from Plextronics), and copolymerssuch as poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) alsocalled PEDOT/PSS. Further suitable hole injection materials arementioned in US2013/0181190, especially in table 3, and US2013/0119354,especially in table 4.

It is possible to use as hole injection materials p-doped layers.Suitable p-dopants are mentioned below concerning the hole transportlayer. Examples for suitable p-dopants are MoO₃, F4-TCNQ or NDP-9. It isfurther possible to use layers of p-dopants itself. Suitable p-dopantsare mentioned below concerning the hole transport layer. Examples forsuitable p-dopants are MoO₃, F4-TCNQ or NDP-9.

Further suitable hole injection materials are described inUS2006/0188745, US2006/0240280 and US2007/0092755, whereby the followingmaterial is an example for a preferred hole injection material:

Further suitable hole injection materials are described inUS2010/0219400, US2015/0073142 and US2015/0102331, whereby the followingmaterial is an example for a preferred hole injection material:

preferably doped with MoO₃, F4-TCNQ or NDP-9, more preferably doped withNDP-9.

The dopant NDP-9 is commercially available and for example described inEP 2 180 029. Further suitable hole injection materials are thefollowing materials:

Further compounds suitable as hole injection material are for examplementioned in US2010/0044689 and US2014/0217392, e.g. the followingcompound

doped with a p-dopant. Suitable p-dopants are mentioned below concerningthe hole transport layer. Examples for suitable p-dopants are MoO₃,F4-TCNQ or NDP-9.

Further compounds suitable as hole injection material are for examplementioned in US2010/0219400, US2015/0073142 and US2015/0102331, e.g. thefollowing compound

doped with a p-dopant. Suitable p-dopants are mentioned below concerningthe hole transport layer. Examples for suitable p-dopants are MoO₃,F4-TCNQ or NDP-9.

Further compounds suitable as hole injection material are for examplementioned in US2008/0014464, e.g. the following compound

doped with a p-dopant. Suitable p-dopants are mentioned below concerningthe hole transport layer. Examples for suitable p-dopants are MoO₃,F4-TCNQ or NDP-9(N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1-biphenyl)-4,4′-diamine).F4-TCNQ:

In addition to the hole injection materials mentioned above, thematerials mentioned as hole transport materials in the hole transportlayer are also useful as hole injection materials, especially incombination with a p-dopant, for example in combination with MoO₃,F4-TCNQ or NDP-9. Further suitable p-dopants are mentioned below (seehole transport layer (c)).

Hole Transport Layer (c)

Either hole-transporting molecules or polymers may be used as the holetransport material. Suitable hole transport materials for layer (c) ofthe inventive OLED are disclosed, for example, in Kirk-OthmerEncyclopedia of Chemical Technology, 4th Edition, Vol. 18, pages 837 to860, 1996, US20070278938, US2008/0106190, US2011/0163302 (triarylamineswith (di)benzothiophen/(di)benzofuran; Nan-Xing Hu et al. Synth. Met.111 (2000) 421 (indolocarbazoles), WO2010/002850 (substitutedphenylamine compounds), WO2012/16601 (in particular the hole transportmaterials mentioned on pages 16 and 17 of WO2012/16601), US2013/0181190,especially in table 3, and US2013/0119354, especially in table 4.Further suitable hole transport materials are mentioned inUS20120223296. Combination of different hole transport material may beused. Reference is made, for example, to WO2013/022419, wherein

constitute the hole transport layer.

Customarily used hole-transporting molecules are selected from the groupconsisting of

(4-phenyl-N-(4-phenylphenyl)-N-[4-[4-(N-[4-(4-phenyl-phenyl)phenyl]anilino)phenyl]phenyl]aniline),

(4-phenyl-N-(4-phenylphenyl)-N-[4-[4-(4-phenyl-N-(4-phenylphenyl)anilino)phenyl]phenyl]aniline),

(4-phenyl-N-[4-(9-phenylcarbazol-3-yl)phenyl]-N-(4-phenylphenyl)aniline),

(1,1′,3,3′-tetraphenylspiro[1,3,2-benzodiazasilole-2,2′-3a,7a-dihydro-1,3,2-benzodiazasilole]),

(N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(p-tolyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetramine),4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD),N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),α-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenylhydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)2-methylphenyl](4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol9-yl)-cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),fluorine compounds such as2,2′,7,7′-tetra(N,N-di-tolyl)amino9,9-spirobifluorene (spiro-TTB),N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)9,9-spirobifluorene(spiro-NPB) and9,9-bis(4-(N,N-bis-biphenyl-4-yl-amino)phenyl-9Hfluorene, benzidinecompounds such as N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidineand porphyrin compounds such as copper phthalocyanines. In addition,polymeric hole-injection materials can be used such aspoly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole, polyaniline,self-doping polymers, such as, for example, sulfonatedpoly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl) (Plexcore® OCConducting Inks commercially available from Plextronics), and copolymerssuch as poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) alsocalled PEDOT/PSS.

In a preferred embodiment it is possible to use metal carbene complexesas hole transport materials. Suitable carbene complexes are, forexample, carbene complexes as described in WO2005/019373A2,WO2006/056418 A2, WO2007/115970, WO2007/115981, WO2008/000727,WO2012/121936A2, US2012/0305894A1, and WO2012/172482A1. One example of asuitable carbene complex is Ir(DPBIC)₃ (HTM-1). Another example of asuitable carbene complex is Ir(ABIC)₃ (HTM-2). The formulae of (HTM-1)and (HTM-2) are mentioned above.

Further compounds suitable as hole transport material are for examplementioned in US2010/0044689 and US2014/0217392, e.g. the followingcompound

The compounds are employed in the hole transport layer in doped orundoped form. Suitable dopants are mentioned below.

Further compounds suitable as hole transport material are for examplementioned in US2010/0219400, US2015/0073142 and US2015/0102331, e.g. thefollowing compound

The compounds are employed in the hole transport layer in doped orundoped form. Suitable dopants are mentioned below.

Further compounds suitable as hole transport material are for examplementioned in US2008/0014464, e.g. the following compound

The compounds are employed in the hole transport layer in doped orundoped form. Suitable dopants are mentioned below.

Further compounds suitable as hole transport material are for examplementioned in WO2013/112557, e.g. the following compounds 1a to 12amentioned in WO2013/112557:

The hole-transporting layer may also be electronically doped in order toimprove the transport properties of the materials used, in order firstlyto make the layer thicknesses more generous (avoidance of pinholes/shortcircuits) and in order secondly to minimize the operating voltage of thedevice. Electronic doping is known to those skilled in the art and isdisclosed, for example, in W. Gao, A. Kahn, J. Appl. Phys., Vol. 94,2003, 359 (p-doped organic layers); A. G. Werner, F. Li, K. Harada, M.Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., Vol. 82, No. 25, 2003,4495 and Pfeiffer et al., Organic Electronics 2003, 4, 89-103 and K.Walzer, B. Maennig, M. Pfeiffer, K. Leo, Chem. Soc. Rev. 2007, 107,1233. For example it is possible to use mixtures in thehole-transporting layer, in particular mixtures which lead to electricalp-doping of the hole-transporting layer. p-Doping is achieved by theaddition of oxidizing materials. These mixtures may, for example, be thefollowing mixtures: mixtures of the abovementioned hole transportmaterials with at least one metal oxide, for example MoO₂, MoO₃, WO_(x),ReO₃ and/or V₂O₅, preferably MoO₃ and/or ReO₃, more preferably MoO₃, ormixtures comprising the aforementioned hole transport materials and oneor more compounds selected from 7,7,8,8-tetracyanoquinodimethane (TCNQ),2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄-TCNQ),2,5-bis(2-hydroxyethoxy)-7,7,8,8-tetracyanoquinodimethane,bis(tetra-n-butylammonium)tetracyanodiphenoquinodimethane,2,5-dimethyl-7,7,8,8-tetra-cyanoquinodimethane, tetracyanoethylene,11,11,12,12-tetracyanonaphtho2,6-quinodimethane,2-fluoro-7,7,8,8-tetracyanoquino-dimethane,2,5-difluoro-7,7,8,8etracyanoquinodimethane,dicyanomethylene-1,3,4,5,7,8-hexafluoro-6Hnaphthalen-2-ylidene)malononitrile(F₆-TNAP), Mo(tfd)₃ (from Kahn et al., J. Am. Chem. Soc. 2009, 131 (35),12530-12531), compounds as described in EP1988587, US2008/265216,EP2180029, US2010/0102709, WO2010/132236, EP2180029 and quinonecompounds as mentioned in EP2401254; as well as compounds as describedin EP1713136 and WO2007/071450 and US2008/0265216.

Further materials useful in the hole transport layer are the followingmaterials:

as well as NHT-49, NHT-51 (NHT-49, NHT-51 are commercially availablefrom Novaled).

In addition to the hole transport materials mentioned above, thematerials mentioned as hole injection materials in the hole injectionlayer are also useful as hole transport materials. Said materials may beused in undoped form or in combination with a p-dopant, for example incombination with MoO₃, F4-TCNQ or NDP-9, in the hole transport layer.

Electron/Exciton Blocking Layer (d)

Blocking layers may be used to reduce the number of charge carriers(electrons or holes) and/or excitons that leave the emissive layer. Anelectron/exciton blocking layer (d) may be disposed between the emittinglayer (e) and the hole transport layer (c), to block electrons fromemitting layer (e) in the direction of hole transport layer (c).Blocking layers may also be used to block excitons from diffusing out ofthe emissive layer. Suitable metal complexes for use as electron/excitonblocker material are, for example, carbene complexes as described inWO2005/019373A2, WO2006/056418A2, WO2007/115970, WO2007/115981,WO2008/000727, WO2012/121936A2, US2012/0305894A1, and WO2012/172482A1.Explicit reference is made here to the disclosure of the WO applicationscited, and these disclosures shall be considered to be incorporated intothe content of the present application. One example of a suitablecarbene complex is compound HTM-1. Another example of a suitable carbenecomplex is compound HTM-2. The formulae of (HTM-1) and (HTM-2) arementioned above.

Also suitable as electron/exciton blocker materials are the compoundsmentioned in WO2012/130709; WO2013/050401; WO2014/009317; WO2014/044722;and the non-published European Patent Application EP13191100.0.

Further suitable electron/exciton blocker materials are the compounds offormula (H1) mentioned in WO2013/112557, as described above.

Further suitable electron/exciton blocker materials are the compoundsmentioned in US2012/0223296.

Especially suitable are the compounds (H1-1), (H1-2), (H1-7) asmentioned above and the compounds (H1-3), (H1-4), (H1-5), (H1-6),(H1-8), (H1-9), (H1-10), (H1-11), (H1-12), (H1-13), (H1-14), (H1-14),(H-16) and (H1-17) as described in WO 2013/112557.

(Further suitable electron/exciton blocker materials are: NHT-49, NHT-51(which are commercially available from Novaled) and HTM-211,

Further compounds suitable as electron/exciton blocker materials are forexample mentioned in US2010/0044689 and US2014/0217392, e.g. thefollowing compound

Further compounds suitable as electron/exciton blocker materials are forexample mentioned in US2010/0219400, US2015/0073142 and US2015/0102331,e.g. the following compound

Further compounds suitable as electron/exciton blocker materials are forexample mentioned in US2008/0014464, e.g. the following compound

Hole/Exciton Blocking Layer (f)

Blocking layers may be used to reduce the number of charge carriers(electrons or holes) and/or excitons that leave the emissive layer. Thehole blocking layer may be disposed between the emitting layer (e) andelectron transport layer (g), to block holes from leaving layer (e) inthe direction of electron transport layer (g). Blocking layers may alsobe used to block excitons from diffusing out of the emissive layer.Suitable hole/exciton blocking materials are, in principle, the hostcompounds mentioned above. The same preferences apply as for the hostmaterial.

Suitable hole/exciton blocker materials are therefore for example thematerials containing both triphenylene and benzo-fused furans orbenzo-fused thiophenes as mentioned above concerning suitable hostmaterials.

Further hole/exciton blocking materials are one or more compounds of thegeneral formula (X)

whereinX is NR, S, O or PR;R is aryl, heteroaryl, alkyl, cycloalkyl, or heterocycloalkyl;A²⁰⁰ is —NR²⁰⁶R²⁰⁷, —P(O)R²⁰⁸R²⁰⁹, —PR²¹⁰R²¹¹, —S(O)₂R²¹², —S(O)R²¹³,—SR²¹⁴, or —OR²¹⁵;R²²¹, R²²² and R²²³ are independently of each other aryl, heteroaryl,alkyl, cycloalkyl, or heterocycloalkyl, wherein at least on of thegroups R²²¹, R²²², or R²²³ is aryl, or heteroaryl;R²²⁴ and R²²⁵ are independently of each other alkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, a group A²⁰⁰, or a group havingdonor, or acceptor characteristics;n2 and m2 are independently of each other 0, 1, 2, or 3;R²⁰⁶ and R²⁰⁷ form together with the nitrogen atom a cyclic residuehaving 3 to 10 ring atoms, which can be unsubstituted, or which can besubstituted with one, or more substituents selected from alkyl,cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a group having donor,or acceptor characteristics; and/or which can be annulated with one, ormore further cyclic residues having 3 to 10 ring atoms, wherein theannulated residues can be unsubstituted, or can be substituted with one,or more substituents selected from alkyl, cycloalkyl, heterocycloalkyl,aryl, heteroaryl and a group having donor, or acceptor characteristics;andR²⁰⁸, R²⁰⁹, R²¹⁰, R²¹¹, R²¹², R²¹³, R²¹⁴ and R²¹⁵ are independently ofeach other aryl, heteroaryl, alkyl, cycloalkyl, or heterocycloalkyl.

Compounds of formula (X) are described in WO2010/079051 (in particularpages on 19 to 26 and in tables on pages 27 to 34, pages 35 to 37 andpages 42 to 43).

Further suitable hole/exciton blocker materials are mentioned inUS2013/0181190, especially in table 3, and US 2013/0119354, especiallyin table 4. Further suitable hole/exciton blocker materials arementioned in US2014/0001446 and WO2015/014791.

Examples are bathocuprine compounds such as:

metal-8-hydroxy-quinolates such as:

triazoles, oxadiazoles, imidazoles, benzoimidazoles, triphenylenecompounds, fluorinated aromatic compounds, phenothiazine-S-oxides,silylated five-membered nitrogen, oxygen, sulfur or phosphorousdibenzoheterocycles, or Aza-carbazoles.

Electron Transport Layer (g)

Electron transport layer may include a material capable of transportingelectrons. Electron transport layer may be intrinsic (undoped), ordoped. Doping may be used to enhance conductivity. Suitableelectron-transporting materials for layer (g) of the inventive OLEDscomprise metals chelated with oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq₃), compounds based onphenanthroline such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(DDPA=BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen),2,4,7,9-tetraphenyl-1,10-phenanthroline,4,7-diphenyl-1,10-phenanthroline (DPA) or phenanthroline derivativesdisclosed in EP1786050, in EP1970371, or in EP1097981, and azolecompounds such as 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole(PBD) and 3-(4-biphenylyl)-4phenyl-5-(4-t-butylphenyl)-1,2,4-triazole(TAZ).

It is likewise possible to use mixtures of at least two materials in theelectron-transporting layer, in which case at least one material iselectron-conducting. Preferably, in such mixed electron-transportinglayers, at least one phenanthroline compound is used, preferably BCP, orat least one pyridine compound according to the formula (VIII) below,preferably a compound of the formula (VIIIaa) below. More preferably, inmixed electron-transporting layers, in addition to at least onephenanthroline compound, alkaline earth metal or alkali metalhydroxyquinolate complexes, for example Liq, are used. Suitable alkalineearth metal or alkali metal hydroxyquinolate complexes are specifiedbelow (formula VII). Reference is made to WO2011/157779.

The electron-transporting layer may also be electronically doped inorder to improve the transport properties of the materials used, inorder firstly to make the layer thicknesses more generous (avoidance ofpinholes/short circuits) and in order secondly to minimize the operatingvoltage of the device. Electronic doping is known to those skilled inthe art and is disclosed, for example, in W. Gao, A. Kahn, J. Appl.Phys., Vol. 94, No. 1, 1 Jul. 2003 (p-doped organic layers); A. G.Werner, F. Li, K. Harada, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys.Lett., Vol. 82, No. 25, 23 Jun. 2003 and Pfeiffer et al., OrganicElectronics 2003, 4, 89-103 and K. Walzer, B. Maennig, M. Pfeiffer, K.Leo, Chem. Soc. Rev. 2007, 107, 1233. For example, it is possible to usemixtures which lead to electrical n-doping of the electron-transportinglayer. n-Doping is achieved by the addition of reducing materials. Thesemixtures may, for example, be mixtures of the abovementioned electrontransport materials with alkali/alkaline earth metals or alkali/alkalineearth metal salts, for example Li, Cs, Ca, Sr, Cs₂CO₃, with alkali metalcomplexes, for example 8-hydroxyquinolatolithium (Liq), and with Y, Ce,Sm, Gd, Tb, Er, Tm, Yb, Li₃N, Rb₂CO₃, dipotassium phthalate, W(hpp)₄from EP1786050, or with compounds described in EP1837926B1, EP1837927,EP2246862, WO2010132236 and DE102010004453.

In a preferred embodiment, the electron-transporting layer comprises atleast one compound of the general formula (VII)

in whichR³² and R³³ are each independently F, C₁-C₈-alkyl, or C₆-C₁₄-aryl, whichis optionally substituted by one or more C₁-C₈-alkyl groups, ortwo R³² and/or R³³ substituents together form a fused benzene ring whichis optionally substituted by one or more C₁-C₈-alkyl groups;a and b are each independently 0, or 1, 2 or 3,M¹ is an alkaline metal atom or alkaline earth metal atom,p is 1 when M¹ is an alkali metal atom, p is 2 when M¹ is an earthalkali metal atom.

A very particularly preferred compound of the formula (VII) is

which may be present as a single species, or in other forms such asLi_(g)Q_(g) in which g is an integer, for example Li₆Q₆. Q is an8-hydroxyquinolate ligand or an 8-hydroxyquinolate derivative.

In a further preferred embodiment, the electron-transporting layercomprises at least one compound of the formula (VIII),

in whichR³⁴, R³⁵, R³⁶, R³⁷, R^(34′), R^(35′), R^(36′) and R^(37′) are eachindependently H, C₁-C₁₈-alkyl, C₁-C₁₈-alkyl which is substituted by Eand/or interrupted by D, C₆-C₂₄-aryl, C₆-C₂₄-aryl which is substitutedby G, C₂-C₂₀-heteroaryl or C₂-C₂₀-heteroaryl which is substituted by G,Q is an arylene or heteroarylene group, each of which is optionallysubstituted by G;D is —CO—; —COO—; —S—; —SO—; —SO₂—; —O—; —NR⁴⁰—; —SiR⁴⁵R⁴⁶—; —POR⁴⁷—;—CR³⁸═CR³⁹—; or —C≡C—;E is —OR⁴⁴; —SR⁴⁴; —NR⁴⁰R⁴¹; —COR⁴³; —COOR⁴²; —CONR⁴⁰R⁴¹; —CN; or F;G is E, C₁-C₁₈-alkyl, C₁-C₁₈-alkyl which is interrupted by D,C₁-C₁₈-perfluoroalkyl, C₁-C₁₈-alkoxy, or C₁-C₁₈-alkoxy which issubstituted by E and/or interrupted by D,in whichR³⁸ and R³⁹ are each independently H, C₆-C₁₈-aryl; C₆-C₁₈-aryl which issubstituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; orC₁-C₁₈-alkyl which is interrupted by —O—;R⁴⁰ and R⁴¹ are each independently C₆-C₁₈-aryl; C₆-C₁₈-aryl which issubstituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; orC₁-C₁₈-alkyl which is interrupted by —O—; orR⁴⁰ and R⁴¹ together form a 6-membered ring;R⁴² and R⁴³ are each independently C₆-C₁₈-aryl; C₆-C₁₈-aryl which issubstituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; orC₁-C₁₈-alkyl which is interrupted by —O—,R⁴⁴ is C₆-C₁₈-aryl; C₆-C₁₈-aryl which is substituted by C₁-C₁₈-alkyl orC₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; or C₁-C₁₈-alkyl which is interrupted by—O—,R⁴⁵ and R⁴⁶ are each independently C₁-C₁₈-alkyl, C₆-C₁₈-aryl orC₆-C₁₈-aryl which is substituted by C₁-C₁₈-alkyl,R⁴⁷ is C₁-C₁₈-alkyl, C₆-C₁₈-aryl or C₆-C₁₈-aryl which is substituted byC₁-C₁₈-alkyl.

Preferred compounds of the formula (VIII) are compounds of the formula(VIIIa)

in which Q is:

R⁴⁸ is H or C₁-C₁₈-alkyl andR^(48′) is H, C₁-C₁₈-alkyl or

Particular preference is given to a compound of the formula

In a further, very particularly preferred embodiment, theelectron-transporting layer comprises a compound Liq and a compoundETM-2.

In a preferred embodiment, the electron-transporting layer comprises thecompound of the formula (VII) in an amount of 99 to 1% by weight,preferably 75 to 25% by weight, more preferably about 50% by weight,where the amount of the compounds of the formulae (VII) and the amountof the compounds of the formulae (VIII) adds up to a total of 100% byweight.

The preparation of the compounds of the formula (VIII) is described inJ. Kido et al., Chem. Commun. (2008) 5821-5823, J. Kido et al., Chem.Mater. 20 (2008) 5951-5953 and JP2008/127326, or the compounds can beprepared analogously to the processes disclosed in the aforementioneddocuments.

It is likewise possible to use mixtures of alkali metal hydroxyquinolatecomplexes, preferably Liq, and dibenzofuran compounds in theelectron-transporting layer. Reference is made to WO2011/157790.Dibenzofuran compounds A-1 to A-36 and B-1 to B-22 described inWO2011/157790 are preferred, wherein dibenzofuran compound

(A-10; =ETM-1) is most preferred.

In a preferred embodiment, the electron-transporting layer comprises Liqin an amount of 99 to 1% by weight, preferably 75 to 25% by weight, morepreferably about 50% by weight, where the amount of Liq and the amountof the dibenzofuran compound(s), especially ETM-1, adds up to a total of100% by weight.

In a preferred embodiment, the electron-transporting layer comprises atleast one phenanthroline derivative and/or pyridine derivative.

In a further preferred embodiment, the electron-transporting layercomprises at least one phenanthroline derivative and/or pyridinederivative and at least one alkali metal hydroxyquinolate complex.

In a further preferred embodiment, the electron-transporting layercomprises at least one of the dibenzofuran compounds A-1 to A-36 and B-1to B-22 described in WO2011/157790, especially ETM-1.

In a further preferred embodiment, the electron-transporting layercomprises a compound described in WO2012/111462, WO2012/147397,WO2012/014621, such as, for example, a compound of formula

US2012/0261654, such as, for example, a compound of formula

and WO2012/115034, such as for example, such as, for example, a compoundof formula

Further suitable electron transport materials are mentioned inUS2013/0181190, especially in table 3, and US2013/0119354, especially intable 4.

Further suitable electron transport materials are mentioned inWO2013/079678, especially the compounds mentioned in the examples.

Further suitable electron transport materials are mentioned inEP2452946, especially compound (28) on page 5 and compound (10) on page6.

A further suitable electron transport material is

Further suitable electron transport materials are mentioned in EP2434559and WO2013/187896, for example:

As n-dopant, for example the material mentioned in EP 1 837 926 isemployed.

Electron Injection Layer (h)

The electron injection layer may be any layer that improves theinjection of electrons into an adjacent organic layer.Lithium-comprising organometallic compounds such as8-hydroxyquinolatolithium (Liq), CsF, NaF, KF, Cs₂CO₃ or LiF may beapplied between the electron transport layer (g) and the cathode (i) asan electron injection layer (h) in order to reduce the operatingvoltage.

Cathode (i)

The cathode (i) is an electrode which serves to introduce electrons ornegative charge carriers. The cathode may be any metal or nonmetal whichhas a lower work function than the anode. Suitable materials for thecathode are selected from the group consisting of alkali metals of group1, for example Li, Cs, alkaline earth metals of group 2, metals of group12 of the Periodic Table of the Elements, comprising the rare earthmetals and the lanthanides and actinides. In addition, metals such asaluminum, indium, calcium, barium, samarium and magnesium, andcombinations thereof, may be used.

In general, the different layers, if present, have the followingthicknesses: In general, the different layers in the inventive OLED, ifpresent, have the following thicknesses:

anode (a): 12 to 500 nm, preferably 40 to 500, more preferably 50 to 500nm, most preferably 100 to 200 nm; in a further most preferredembodiment: 40 to 120 nm; hole injection layer (b): 1 to 100 nm,preferably 5 to 100 nm, more preferably 2 to 80 nm, most preferably 20to 80 nm,hole-transport layer (c): 5 to 200 nm, preferably 5 to 100 nm, morepreferably 10 to 80 nm;electron/exciton blocking layer (d): 1 to 50 nm, preferably 5 to 10 nm,preferably 3 to 10 nm;light-emitting layer (e): 1 to 100 nm, preferably 5 to 60 nm, preferably5 to-40 nm;hole/exciton blocking layer (f): 1 to 50 nm, preferably 5 to 10 nm,preferably 3 to 10 nm;electron-transport layer (g): 5 to 100 nm, preferably 20 to 80 nm;preferably 20 to 50 nm;electron injection layer (h): 1 to 50 nm, preferably 2 to 10 nm;cathode (i): 20 to 1000 nm, preferably 30 to 500 nm.

The inventive OLED can be produced by methods known to those skilled inthe art. In general, the OLED is produced by successive vapor depositionof the individual layers onto a suitable substrate. Suitable substratesare, for example, glass, inorganic materials such as ITO or IZO orpolymer films. For the vapor deposition, customary techniques may beused, such as thermal evaporation, chemical vapor deposition (CVD),physical vapor deposition (PVD) and others. In case of an active matrixOLED display (AMOLED), the substrate can be an AMOLED backplane.

In an alternative process, the organic layers may be coated fromsolutions or dispersions in suitable solvents, in which case coatingtechniques known to those skilled in the art are employed. Suitablecoating techniques are, for example, spin-coating, the casting method,the Langmuir-Blodgett (“LB”) method, the inkjet printing method,dip-coating, letterpress printing, screen printing, doctor bladeprinting, slit-coating, roller printing, reverse roller printing, offsetlithography printing, flexographic printing, web printing, spraycoating, coating by a brush or pad printing, and the like. Among theprocesses mentioned, in addition to the aforementioned vapor deposition,preference is given to spin-coating, the inkjet printing method and thecasting method since they are particularly simple and inexpensive toperform. In the case that layers of the OLED are obtained by thespin-coating method, the casting method or the inkjet printing method,the coating can be obtained using a solution prepared by dissolving thecomposition in a concentration of 0.0001 to 90% by weight in a suitableorganic solvent such as benzene, toluene, xylene, tetrahydrofuran,methyltetrahydrofuran, N,N-dimethylformamide, acetone, acetonitrile,anisole, dichloromethane, dimethyl sulfoxide, water and mixturesthereof.

It is possible that the layers of the OLED are all produced by the samecoating method. Furthermore, it is likewise possible to conduct two ormore different coating methods to produce the layers of the OLED.

The inventive OLEDs can be used in all devices in whichelectroluminescence is useful. Suitable devices are preferably selectedfrom stationary and mobile visual display units and illumination means.Further suitable devices are devices such as keyboards; items ofclothing; furniture; and wallpaper. The present invention therefore alsorelates to a device selected from the group consisting of stationaryvisual display units; mobile visual display units; illumination means;keyboards; items of clothing; furniture; and wallpaper comprising aninventive OLED or an inventive light-emitting layer.

Stationary visual display units are, for example, visual display unitsof computers, televisions, visual display units in printers, kitchenappliances and advertising panels, illuminations and information panels.Mobile visual display units are, for example, visual display units incellphones, laptops, tablet PCs, digital cameras, mp-3 players,smartphones, vehicles, and destination displays on buses and trains.

The inventive metal carbene complexes can additionally be used in OLEDswith inverse structure. In these inverse OLEDs, the inventive complexesare in turn preferably used in the light-emitting layer. The structureof inverse OLEDs and the materials typically used therein are known tothose skilled in the art.

The present invention further provides a white OLED comprising at leastone inventive metal carbene complex. In a preferred embodiment, theinventive metal carbene complex is used as emitter material in the whiteOLED. Preferred embodiments of the inventive metal carbene complexeshave been specified above. Suitable structures of white OLEDs andsuitable components are known by a person skilled in the art.

In order to obtain white light, the OLED must generate light whichcolors the entire visible range of the spectrum. However, organicemitters normally emit only in a limited portion of the visiblespectrum—i.e. are colored. White light can be generated by thecombination of different emitters. Typically, red, green and blueemitters are combined. However, the prior art also discloses othermethods for formation of white OLEDs, for example the triplet harvestingapproach. Suitable structures for white OLEDs or methods for formationof white OLEDs are known to those skilled in the art.

In one embodiment of a white OLED, several dyes are layered one on topof another in the light-emitting layer of an OLED and hence combined(layered device). This can be achieved by mixing all dyes or by directseries connection of different-colored layers. The expression “layeredOLED” and suitable embodiments are known to those skilled in the art.

In a further embodiment of a white OLED, several different-colored OLEDsare stacked one on top of another (stacked device). For the stacking oftwo OLEDs, what is called a charge generation layer (CG layer) is used.This CG layer may be formed, for example, from one electrically n-dopedand one electrically p-doped transport layer. The expression “stackedOLED” and suitable embodiments are known to those skilled in the art.

In further embodiments of this “stacked device concept”, it is alsopossible to stack only two or three OLEDs or to stack more than threeOLEDs.

In a further embodiment of white OLEDs, the two concepts mentioned forwhite light generation can also be combined. For example, a single-colorOLED (for example blue) can be stacked with a multicolor layered OLED(for example red-green). Further combinations of the two concepts areconceivable and known to those skilled in the art.

The inventive metal carbene complex can be used in any of the layersmentioned above in white OLEDs. In a preferred embodiment, it is used inone or more or all light-emitting layer(s) of the OLED(s), in which casethe structure of the invention metal carbene complex is varied as afunction of the use of the complex. Suitable and preferred componentsfor the further layers of the light OLED(s) or materials suitable asmatrix material in the light-emitting layer(s) and preferred matrixmaterials are likewise specified above.

The examples which follow, more particularly the methods, materials,conditions, process parameters, apparatus and the like detailed in theexamples, are intended to support the present invention, but not torestrict the scope of the present invention.

EXAMPLES

All experiments are carried out in protective gas atmosphere. Thepercentages and ratios mentioned in the examples below—unless statedotherwise—are % by weight and weight ratios.

I. Synthesis Examples Synthesis Example 1 Synthesis of Complex (I) a)Synthesis of N2,N3-bis(4-isopropylphenyl)quinoxaline-2,3-diamine

10.0 g (50.2 mmol) of 2,3-dichloroquinoxaline and 14.5 g (0.11 mol)4-isopropylaniline in 90 ml of o-xylene are heated at 150° C. during 90minutes followed by stirring the resulting yellow suspension at roomtemperature during 16 hours. The thick yellow suspension is diluted with140 ml of o-xylene and heating is continued at 160° C. for another twohours. The suspension is cooled down to room temperature and dilutedwith heptane up to a total volume of 500 ml. The thick suspension isstirred during 20 minutes, filtered, followed by washing with ethanol,and the resulting yellow solid dried under vacuum. The solid issuspended in a mixture of 100 ml of ethanol, 100 ml of water and 50 mlof 25% aqueous ammonia solution, and the resulting suspension stirredduring 15 minutes, providing a light brown emulsion. The emulsion isdiluted with water and extracted with dichloromethane. Thedichloromethane phase is separated and the aqueous phase extracted withan additional amount of dichloromethane. The combined dichloromethanefractions are washed with water, dried over magnesium sulfate, filteredand concentrated under vacuum. The yellow-brown oil is purified bychromatography (silica gel, heptane/ethyl acetate) giving the titleproduct as a yellow solid (yield: 12.4 g (65%)).

¹H-NMR (400 MHz, CD₃OD): δ=1.27 (d, 12H), 2.90 (m, 2H), 7.24 (m, 4H),7.30 (m, 2H), 7.56 (m, 2H), 7.69 (m, 4H).

b) Synthesis of[3-(4-isopropylanilino)quinoxalin-2-yl]-(4-isopropylphenyl)ammoniumchloride

An orange suspension of 12.4 g (31.3 mmol) ofN2,N3-bis(4-isopropylphenyl)quinoxaline-2,3-diamine and 250 ml of 37%hydrochloric acid solution is stirred at room temperature during onehour. The yellow suspension is carefully diluted with water and stirringcontinued for 10 minutes. The suspension is filtered and the solidwashed with water and further dried under vacuum giving the titleproduct as a yellow solid (yield: 22.0 g, still wet).

c) Synthesis of2-ethoxy-1,3-bis(4-isopropylphenyl)-2H-imidazo[4,5-b]quinoxaline

22 g (max. 31 mmol, still including residual water) of[3-(4-isopropylanilino)quinoxalin-2-yl]-(4-isopropylphenyl)ammoniumchloride and 200 ml (1.2 mol) of triethyl orthoformate are heated underargon at 95° C. during 90 minutes. The light yellow-greenish turbidsolution is cooled down and triethyl orthoformate distilled off undervacuum. 50 ml of ethanol are added and the resulting suspension stirredover an ice-bath. The suspension is filtered and the solid washed with25 ml of ethanol giving the title product as a white solid (yield: 12.1g (86%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.91 (t, 3H), 1.26 (d, 12H), 2.96 (m, 2H),3.28 (m, 2H), 7.37 (m, 2H), 7.42 (m, 4H), 7.61 (m, 2H), 7.78 (s, 1H),8.02 (m, 4H).

d) Synthesis of Complex (I)

4.00 g (8.84 mmol) of2-ethoxy-1,3-bis(4-isopropylphenyl)-2H-imidazo[4,5-b]quinoxaline and0.60 g (0.89 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended under argon in 70 ml of o-xylene. The orange suspension isthree times evacuated and backfilled with argon, followed by heating at142° C. during 9 hours. The solution is cooled down to room temperatureand concentrated under vacuum. The solid is treated with ethanol andstirred at room temperature during one hour. The suspension is filteredand the solid further purified by chromatography (silica gel,heptane/dichloromethane). The resulting solid is dissolved in 50 ml ofdichloromethane followed by the addition of 250 ml of ethanol. Theresulting yellow suspension is stirred at room temperature during 30minutes, then filtered, the solid washed with ethanol, dried undervacuum, giving the title product as a bright yellow solid (yield: 1.90 g(75%)).

APCI-LC-MS (positive, m/z): exact mass of C₈₁H₇₅IrN₁₂=1408.59; found1409.7 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.70 (d, 9H), 0.80 (d, 9H), 1.01 (d, 9H),1.11 (d, 9H), 2.11 (m, 3H), 2.66 (m, 3H), 6.05 (br. s, 3H), 6.35-6.79(2×br. s, and d, 9H), 7.12 (dd, 3H), 7.37 (br. s, 3H), 7.72 (m, 3H),7.84 (m, 6H), 8.35 (d, 3H), 8.99 (d, 3H).

Synthesis Example 2 Synthesis of Complex (II) a) Synthesis of ComplexIntermediate (II-1)

5.27 g (7.85 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended in 250 ml of toluene and three times evacuated and backfilledwith argon. 5.00 g (15.7 mmol) of2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine are added in smallportions at 66° C. during 20 minutes. Heating is continued at 66° C. andthe generated ethanol continuously removed by using a distillationbridge. The yellow-brown suspension is cooled down to room temperatureand diluted with 200 ml of ethanol, and cooling is continued until 5° C.is reached. Stirring is continued at this temperature for 30 minutes,followed by filtration and washing with 50 ml of cold ethanol and 50 mlof heptane. The resulting solid is dried under vacuum giving the titleproduct as a yellow solid (yield: 4.1 g (43%)).

¹H-NMR (400 MHz, CDCl₃): δ=1.31-1.42 (m, 2H), 1.43-1.64 (m, 4H),1.73-1.86 (m, 2H), 2.50-2.59 (m, 2H), 4.68-4.78 (m, 2H), 7.57-7.69 (m,6H), 8.15-8.22 (m, 4H), 8.33 (s, 2H).

b) Synthesis of Complex (II)

0.3 g (0.5 mmol) of intermediate complex (II-1) and 0.49 g (1.08 mmol)of 2-ethoxy-1,3-bis(4-isopropylphenyl)-2H-imidazo[4,5-b]quinoxaline aredissolved under argon in 50 ml of o-xylene. The yellow turbid solutionis three times evacuated and backfilled with argon, followed by heatingat 140° C. during 10 hours. The reaction mixture is cooled down to 50°C. and directly purified by elution via chromatography (silica gel,toluene/ethyl acetat) The product fractions are combined andconcentrated under vacuum. The yellow resin is dissolved in a minimumamount of dichloromethane and treated with ethanol until precipitationis initiated and further stirred over an ice-batch during one hour. Thesuspension is filtered and the solid dried under vacuum, giving thetitle product as a bright yellow solid (yield: 50 mg (18%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₁H₄₇IrN₁₂=1140.37; found1141.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.97 (d, 3H), 1.02 (d, 3H), 1.06 (d, 6H),2.54 (m, 1H), 2.64 (m, 1H), 6.02-7.67 (broad signals, 12H), 6.55 (d,1H), 6.66 (m, 4H), 6.87 (m, 3H), 7.13 (dd, 1H), 7.20 (m, 2H), 7.84 (ddd,1H), 7.90 (dd, 1H), 8.09 (dd, 2H), 8.31-8.43 (m, 3H), 8.78 (dd, 1H),8.85 (dd, 1H), 8.97 (d, 1H).

Synthesis Example 3 Synthesis of Complex (III) a) Synthesis of4,7-diethyl-2,1,3-benzothiadiazole

5.0 g (17.0 mmol) of 4,7-dibromo-2,1,3-benzothiadiazole and 3.77 g (51.0mmol) of ethylboronic acid are suspended under argon in 50 ml oftoluene. 150 mg (0.67 mmol) of palladium(II) acetate and 0.85 g (2.07mmol) of 2-dicyclohexyl-phosphino-2′,6′-dimethoxybiphenyl are added,followed by the addition of 36.1 g (0.16 mol) of potassium phosphatemonohydrate. The yellow suspension is three times evacuated andbackfilled with argon, followed by heating at 110° C. during threehours. The yellow-brown reaction mixture is poured onto 200 ml water and50 ml of toluene, followed by stirring for short time. The water phaseis separated, and the organic phase two times washed with 200 ml ofwater. The organic phase is dried over magnesium sulfate and filtered.The orange solution is further filtered over a 3 cm layer of silica geland the silica gel layer rinsed with toluene. The combined filtrates areconcentrated under vacuum. The resulting yellow oil is cooled down andstirred together with 30 ml of heptane over an ice-bath providing ayellow suspension which is first further stirred during 30 minutes. Thesuspension is filtered, the white solid washed with heptane. Thecombined filtrates are concentrated under vacuum giving the titleproduct as a yellow oil (yield: 3.21 g (98%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.41 (t, 6H), 3.15 (q, 4H), 7.31 (s, 2H).

b) Synthesis of 3,6-diethylbenzene-1,2-diamine

6.90 g (35.9 mmol) of 4,7-diethyl-2,1,3-benzothiadiazole are dissolvedin 150 ml of methanol and heated under reflux. A total of 6.15 g (0.25mol) of magnesium shavings are carefully added in four portions duringone hour, and stirring continued for 30 minutes. The green slightlyturbid solution is cooled down to room temperature and diluted withmethanol up to a volume of 800 ml. The turbid solution is filtered overcellulose filter aid and the filtrate treated with 60 ml of water. Thethick suspension is filtered and the solid rinsed with methanol. Thefiltrates are concentrated under vacuum and the resulting oil dilutedwith dichloromethane. The solution is filtered over a layer of silicagel followed by rinsing of the silica gel with dichloromethane. Thecollected fractions are concentrated under vacuum giving the titleproduct as a yellow oil (yield: 3.52 g (60%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.26 (t, 6H), 2.57 (q, 4H), 3.43 (br. s,4H), 6.62 (s, 2H).

c) Synthesis of 5,8-diethyl-1,4-dihydroquinoxaline-2,3-dione

11.6 g (70.6 mmol) of 3,6-diethylbenzene-1,2-diamine are suspended in130 ml of water and 80 ml of 4N aqueous hydrochloric acid. 9.05 g (71.8mmol) of oxalic acid dihydrate are added and the white suspension heatedunder reflux during 15 hours. The pink suspension is cooled down to roomtemperature, followed by filtration and washing of the solid with water.The solid is stirred in 200 ml of 5% aqueous sodium bicarbonate. Thesuspension is filtered and the solid washed with water, giving the titleproduct as a white solid (yield: 14.3 g (93%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.12 (t, 6H), 2.75 (q, 4H), 6.89 (s, 2H),11.18 (br. s, 2H).

d) Synthesis of 2,3-dichloro-5,8-diethyl-quinoxaline

20.2 g (92.6 mmol) of 5,8-diethyl-1,4-dihydroquinoxaline-2,3-dione areslowly treated at room temperature with 50 ml (0.7 mol) of thionylchloride. The white suspension is heated at 38° C. during two hours,followed by heating at 73° C. during 30 minutes. Thionyl chloride isdistilled off and the yellow oil carefully transferred at roomtemperature into a beaker containing 1000 ml of water. The beigesuspension is stirred during 10 minutes. The suspension is made slightlybasic by the addition of sodium bicarbonate and sodium hydroxide. Thesuspension is further stirred during 10 minutes, followed by filtrationand washing of the solid with water. The beige solid is treated with 100ml of metanol and stirred during 10 minutes. The suspension is filteredand the solid washed with a small amount of metanol, giving the titleproduct as a White solid (yield: 20.2 g (86%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.36 (t, 6H), 3.19 (q, 4H), 7.63 (s, 2H).

e) Synthesis of (3-anilino-5,8-diethyl-quinoxalin-2-yl)-phenyl-ammoniumchloride

8.35 g (32.7 mmol) of 2,3-dichloro-5,8-diethyl-quinoxaline and 50 ml(0.55 mol) of aniline in 100 ml of o-xylene are heated under refluxduring 18 hours. The yellow reaction mixture is cooled down to 50° C.,filtered, and the solid rinsed with o-xylene. The yellow filtrate istreated with 200 ml of water and 50 ml of 25% aqueous ammonia solution,followed by stirring during 10 minutes, and dilution with 250 ml ofheptane. The aqueous phase is separated and the organic phase threetimes washed with 300 ml of water. The organic phase is treated with 200ml of water, and 15 ml of 37% aqueous hydrochlorid acid. The suspensionis filtered and the solid stirred in 300 ml of heptane first, followedby stirring in 300 ml of water. The solid is filtered and dried undervacuum, giving the title product as a light yellow solid (yield: 9.3 g(70%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.28 (t, 6H), 3.00 (q, 4H), 7.06 (m, 2H),7.15 (s, 2H), 7.39 (m, 4H), 8.08 (d, 4H), 9.41 (br. s, 2H).

f) Synthesis of2-ethoxy-5,8-diethyl-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline

9.53 g (23.5 mmol) of(3-anilino-5,8-diethyl-quinoxalin-2-yl)-phenyl-ammonium chloride and 200ml (1.2 mol) of triethyl orthoformate are heated under argon at 95° C.during 90 minutes. The slightly turbid orange solution is concentratedunder vacuum and the resulting solid three times stirred in 50 ml ofheptane. The suspension is filtered and dried under vacuum, giving thetitle product as a light grey solid (yield: 7.5 g (75%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.89 (t, 3H), 1.31 (t, 6H), 3.05 (q, 4H),3.23 (q, 2H), 7.22 (s, 2H), 7.24 (t, 2H), 7.54 (t, 4H), 7.92 (s, 1H),8.28 (d, 4H).

g) Synthesis of Complex (III)

4.00 g (9.42 mmol) of2-ethoxy-5,8-diethyl-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline and 0.63(0.94 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer are suspendedunder argon in 70 ml of o-xylene. The suspension is three timesevacuated and backfilled with argon, followed by heating at 136° C.during 15 hours. The reaction mixture is cooled down to 100° C. andfiltered through a 4.5 cm layer of silica gel. The silica gel layer isrinsed with o-xylene and dichloromethane. The collected filtrates arestirred over an ice-bath during 30 minutes. The suspension is filteredand the solid washed with a small amount of o-xylene, followed by dryingunder vacuum, giving the title product as a bright yellow solid (yield:0.65 g (25%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₅H₆₃IrN₁₂=1324.49; found1325.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.19 (t, 9H), 1.59 (t, 9H), 2.88 (m, 3H),3.00 (m, 3H), 3.49 (m, 6H), 6.49-7.41 (broad signal, 12H), 6.54 (td,3H), 6.76 (dd, 3H), 6.89 (td, 3H), 7.29 (td, 3H), 7.54 (d, 3H), 7.63 (d,3H), 9.09 (d, 3H).

Synthesis Example 4 Synthesis of Complex (IV) a) Synthesis of2,3-dianilino-quinoxaline

2,3-Dianilino-quinoxaline was synthetized similar to the protocoldescribed in J. Chem. Soc. 1948, 777-782. 5.00 g (24.6 mmol)2,3-dichloro-quinoxaline were added in portions to 25 ml aniline at 140°C. The solution was heated to 160° C. and held at that temperature for30 min. 100 ml methyl-tert.-butylether was added to the suspension afterthe solution had cooled down to room temperature. The precipitate wasfiltered off, washed five times with 10 ml methyl-tert.-butylether each,and dried at 30° C. in a vacuum oven. The solid was suspended in 150 mlwater, then filtered off, washed four times with 20 ml water each, andsucked dry. The residue was dissolved in 70 ml methylenechloride.Magnesium sulfate was added. The solution was concentrated. Then 30 mlmethyl-tert.-butylether was added. The suspension was concentrated todryness and dried at 50° C. in a vacuum oven. 8.35 g yellow solid wereobtained. It was used without further purification.

¹H-NMR (500 MHz, d₆-DMSO): δ [ppm]=7.09 (mc; 2H), 7.34 (mc; 2H), 7.41(mc; 4H), 7.55 (mc; 2H), 7.90 (mc; 4H), 9.03 (s; 2H).

b) Synthesis of 2-alkoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline (i)2-Methoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline

16.00 g (51.2 mmol) 2,3-dianilino-quinoxaline and 5.54 g (51.2 mmol)ammonium tetrafluoroborate were dissolved in 64 ml ortho-formic acidtrimethylester. The solution was heated to 82° C. and held at thattemperature for 1.5 h. After cooling to room temperature the suspensionwas filtered. The residue was washed three times with little cold orthoester and then with petrol ether. The solid was dissolved in methylenechloride. The suspension was filtered to separate the product from thesalt. The filtrate was concentrated to dryness. 13.7 g (75% of theory)colorless solid were isolated.

¹H-NMR (400 MHz, CD₂Cl₂): δ [ppm]=3.08 (s; 3H), 7.25 (mc; 2H), 7.36 (s;1H), 7.41 (mc; 2H), 7.51 (mc; 4H), 7.73 (mc; 2H), 8.17 (mc; 4H)

(ii) 2-Ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline

16.35 g (18.7 mmol) 2,3-dianilino-quinoxaline and 0.50 g (4.6 mmol)ammonium tetrafluoroborate were suspended in ortho-formic acidtriethylester. The reaction mixture was heated to reflux for 1 h. Thesolution was cooled to room temperature, filtered, and concentrated todryness. The residue was suspended in pentane, filtered, washed withpentane, and dried. 6.24 g (87% of theory) colorless solid wereobtained.

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=1.04 (t; 3H), 3.36 (q; 2H), 7.26 (mc;2H), 7.35 (s; 1H), 7.41 (mc; 2H), 7.51 (mc; 4H), 7.73 (mc; 2H), 8.20(mc; 4H).

c) Synthesis of Complex (IV)

4.00 g (10.9 mmol) 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxalineand 0.948 g (1.41 mmol) chloro-(1,5-cyclooctadiene)-iridium(I) dimerwere dissolved in 60 ml o-dichloro benzene. The suspension was heated to150° C. and held at that temperature for 20 h. After cooling thesolution to room temperature the precipitate was filtered, washed threetimes with 1.5 ml o-dichloro benzene each, then four times with 2 mlpentane each, and dried in a vacuum oven at 50° C. The solid wassuspended in tetrahydrofurane and heated to reflux for 1 h. The hotsuspension was filtered. The residue was washed with THF, pentane, anddried in a vacuum oven at 70° C. 0.902 g (28% of theory) bright yellowsolid was obtained.

MALDI-MS (positive, m/z): exact mass of C₆₃H₃₉IrN₁₂=1156.28; found 1156[M+H]⁺.

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=6.58 (mc) 6.67 (mc), 6.84 (mc), 7.72(mc), 7.82 (mc), 7.87 (mc), 8.32 (mc), 9.05 (mc).

Synthesis Example 5 Synthesis of Complex (V)

0.250 g 2-Ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline and 0.206 gof intermediate complex (II-1) were dissolved/suspended in 18 mlo-xylene. The suspension was heated to 115° C. and held at thattemperature for 43 h. The precipitate was filtered off after cooling thesolution to room temperature. The filtrate was concentrated to brownresin and then suspended in methylenchloride. The solid was filteredoff. The filtrate was purified at silica gel 60 (70-200 μm) withmethylenchloride as the eluent. The last fractions monitored by TLC werecombined and concentrated to dryness. The yellow solid (64 mg) wassuspended in 5 ml methanol, then filtered off, washed three times with 1ml methanol each, and dried at 60° C. in a vacuum oven. 53 mg (14% oftheory) yellow solid were obtained.

MALDI-MS (positive, m/z): exact mass of C₅₉H₃₇IrN₁₂=1106.22; found 1106[M+H]⁺.

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=6.56-6.89 (m; 18H), 7.15-7.45 (m; 5H),7.45-7.73 (m; 3H), 7.81 (mc; 2H), 7.86 (mc; 2H), 8.08 (mc; 1H), 8.31(mc; 2H), 8.35 (mc; 1H), 8.77 (mc; 1H), 9.04 (mc; 2H).

Synthesis Example 6 Synthesis of Complex (VIa) a) Synthesis ofN2,N3-bis(4-tert-butylphenyl)quinoxaline-2,3-diamine

10.0 g (50.2 mmol) of 2,3-dichloroquinoxaline and 16.5 g (0.11 mol)4-tert-butylaniline in 90 ml of o-xylene are heated at 150° C. duringfive hours. The reaction mixture is cooled down to room temperature,diluted with a small amount of dichloromethane and concentrated undervacuum. The mixture is treated with 200 ml of water, 200 ml of ethanol,and solid sodium carbonate is added until a basic pH is reached. Theorganic phase is separated and the aqueous phase extracted withdichloromethane. The combined organic phases are two times washed withwater, dried over sodium sulfate, and concentrated under vacuum. Theresulting brown oil is mixed with 100 ml of heptane and heated up toreflux, and the solution cooled down to room temperature. The resultingsuspension is filtered, the light yellow solid dissolved in 100 ml ofheptane under reflux, followed by cooling down the solution to roomtemperature. The suspension is filtered and the solid dried undervacuum, giving the title product as a light yellow solid (yield: 13.4 g(63%)).

b) Synthesis of[3-(4-tert-butylanilino)quinoxalin-2-yl]-(4-tert-butylphenyl)ammoniumchloride

13.4 g (31.6 mmol) ofN2,N3-bis(4-tert-butylphenyl)quinoxaline-2,3-diamine are added inseveral portions to 250 ml of concentrated aqueous hydrochloric acid andstirred at room temperature during one hour. The yellow suspension iscarefully diluted with 300 ml of water and stirring continued for tenminutes. The suspension is filtered and the solid washed with water andfurther dried under vacuum, giving the title product as a yellow solid(12.1 g isolated, still including residual water).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.33 (s, 18H), 7.32-7.38 (m, 2H), 7.46 (d,4H), 7.55-7.61 (m, 2H), 7.85 (d, 4H), 10.14 (br. s, 2H).

c) Synthesis of1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxaline

48.3 g (max. 0.1 mol, still including residual water) of[3-(4-tert-butylanilino)quinoxalin-2-yl]-(4-tert-butylphenyl)ammoniumchloride and 250 ml (1.7 mol) of triethyl orthoformate are heated underargon at 95° C. during 30 minutes in a reactor fitted with a Dean-Starkseparator and condenser. 100 ml (0.7 mol) of triethyl orthoformate areadded to the yellow suspension and stirring continued for 30 minutes.Another 100 ml of triethyl orthoformate are added after 30 minutes, andheating continued for one hour. The yellow suspension is cooled down toroom temperature, then filtered, and the yellow solid washed withethanol. The solid is further stirred in 60 ml of ethanol, and thesuspension filtered, followed by drying the solid under vacuum. Thesolid is stirred in 50 ml of heptane, filtered, and dried under vacuum,giving the title product as a light yellow solid (yield: 18.5 g (min.37%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.93 (t, 3H), 1.35 (s, 18H), 3.29 (q, 2H),7.35-7.41 (m, 2H), 7.54-7.65 (2 m, 6H), 7.78 (s, 1H), 8.00-8.08 (m, 4H).

d) Synthesis of Complex (VIa)

8.00 g (16.6 mmol) of1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxaline and1.40 g (2.08 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended under argon in 150 ml of o-xylene. The orange suspension isthree times evacuated and backfilled with argon, followed by heating at134° C. during five hours. The orange-red solution is cooled down toroom temperature and diluted with 200 ml of ethanol. The resultingsuspension is filtered and the yellow solid washed with ethanol. Thesolid is dissolved in 600 ml of dichloromethane and filtered through a 5cm layer of silica gel followed by rinsing the silica gel layer with 300ml of dichloromethane. The collected eluents (orange solution) istreated with 50 ml of ethyl acetate and the solution concentrated undervacuum until a suspension is formed. The suspension is filtered and thesolid washed subsequently with ethyl acetate and ethanol, respectively,followed by drying under vacuum. The solid is dissolved in 500 ml ofdichloromethane and 50 ml of ethyl acetate, and the solutionconcentrated under vacuum until a suspension is formed. The suspensionis filtered, the solid washed with ethyl acetate first, then withethanol, followed by drying under vacuum, giving the title product as ayellow solid (yield: 4.15 g (67%)).

APCI-LC-MS (positive, m/z): exact mass of C₈₇H₈₇IrN₁₂=1492.68; found1493.8 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.79 (s, 27H), 1.10 (s, 27H), 6.09-6.23 (br.signal, 3H), 6.40-6.56 (br. signal, 6H), 6.68 (d, 3H), 7.29 (dd, 3H),7.47-7.62 (br. signal, 3H), 7.68-7.75 (m, 3H), 7.78-7.91 (m, 6H), 8.35(dd, 3H), 9.01 (d, 3H).

Synthesis Example 7 Synthesis of Complex (VII) a) Synthesis of ComplexIntermediate (VII-a)

2.34 g (3.48 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended in 100 ml of toluene. The suspension is three times evacuatedand backfilled with argon and heated up to 77° C. 3.35 g (6.97 mmol) of1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxaline areadded in small portions, and heating continued at 78° C. during 19hours. The brown solution is cooled down to room temperature andconcentrated under vacuum. The resulting red solid is dissolved indichloromethane first, followed by the addition of and 50 ml of ethanol.The solution is concentrated under vacuum until a suspension is formed.The suspension is filtered, the solid washed with ethanol and heptane,followed by drying under vacuum, giving the title product as a yellowsolid (yield: 3.10 g (58%)).

¹H-NMR (400 MHz, CDCl₃): δ=1.30-1.52 (m, 4H), 1.47 (s, 18H), 1.53-1.65(m, 2H), 1.69-1.82 (m, 2H), 2.46-2.55 (m, 2H), 4.72-4.81 (m, 2H), 7.68(d, 2H), 7.73-7.79 (d, 4H), 8.11-8.20 (m, 6H).

b) Synthesis of Complex (VII)

2.50 g (3.24 mmol) of complex intermediate (VII-a) and 2.39 g (6.49mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aresuspended under argon in 50 ml of 1,2-dichlorobenzene. The orange-redsuspension is three times evacuated and backfilled with argon, followedby heating at 117° C. during 20 hours. The reaction mixture is dilutedwith 50 ml of acetone, then filtered, and the solid washed with acetone.The combined filtrates are concentrated under vacuum, then dissolved indichloromethane, followed by the addition of 50 ml of acetone. Thesolution is concentrated under vacuum until a suspension is formed. Thesuspension is filtered, the solid washed with acetone and ethanol,followed by drying under vacuum. The solid is further purified bychromatography (silica gel, dichloromethane), giving the title productas a yellow solid (yield: 1.05 g (25%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₁H₅₅IrN₁₂=1268.43; found1269.6 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.72 (s, 9H), 1.08 (s, 9H), 6.08-8.07 (br.signals, 12H), 6.62-6.76 (m, 5H), 6.86-6.93 (m, 2H), 7.24-7.33 (m, 3H),7.69-7.79 (m, 3H), 7.81-7.88 (m, 4H), 7.88-7.94 (m, 2H), 8.32-8.39 (m,3H), 8.95 (d, 1H), 9.09 (d, 1H), 9.15 (d, 1H).

Synthesis Example 8 Synthesis of Complex (VIII) a) Synthesis of ComplexIntermediate (VIII-a)

3.00 g (4.47 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended in 50 ml of toluene. The suspension is three times evacuatedand backfilled with argon and heated up to 75° C. A solution of 3.29 g(8.92 mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline in 100ml of toluene is added within two hours, and heating continued at 75° C.during 21 hours. The reaction mixture is concentrated under vacuum andthe residue dissolved in dichloromethane and a small amount of ethanol.The solution is concentrated under vacuum until a suspension is formed.The suspension is filtered, the solid washed with ethanol, and furtherdried under vacuum, giving the title product as a yellow solid (yield:2.70 g (46%)).

¹H-NMR (400 MHz, CDCl₃): δ=1.31-1.87 (4 m, 8H), 2.53-2.62 (m, 2H),4.74-4.84 (m, 2H), 7.59-7.72 (m, 6H), 7.73-7.79 (m, 2H), 8.09-8.16 (m,2H), 8.22-8.29 (m, 4H).

b) Synthesis of Complex (VIII)

0.80 g (1.21 mmol) of complex intermediate (VIII-a) and 1.17 g (2.43mmol) of1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxaline aresuspended under argon in 25 ml of o-xylene. The orange suspension isthree times evacuated and backfilled with argon, followed by heating at138° C. during three hours. The orange suspension is cooled down to roomtemperature and filtered. The filtrate is concentrated under vacuum andthe resulting thick oil dissolved in dichloromethane first, followed bythe addition of 30 ml of ethanol. The orange-red solution isconcentrated under vacuum until a suspension is formed. The yellowsuspension is filtered and the solid dried under vacuum. The solid isfurther purified by chromatography (silica gel, heptane/ethyl acetate).The isolated product is dissolved in dichloromethane, followed by theaddition of ethanol. The solution is concentrated under vacuum until asuspension is formed. The suspension is filtered, the solid washed withethanol and further dried under vacuum, giving the title product as ayellow solid (yield: 179 mg (11%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₉H₇₁IrN₁₂=1380.56; found1381.7 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.75 (s, 18H), 1.08 (s, 9H), 1.10 (s, 9H),6.03-7.69 (br. signals, 8H), 6.49 (br. d, 2H), 6.56 (d, 2H), 6.62-6.71(m, 3H), 6.75 (d, 1H), 6.89 (dt, 1H), 7.24-7.32 (m, 3H), 7.69-7.79 (m,3H), 7.79-7.95 (m, 6H), 8.32-8.40 (m, 3H), 8.94 (d, 1H), 9.00 (d, 1H),9.15 (dd, 1H).

Synthesis Example 9 Synthesis of Complex (IX) a) Synthesis of1-methyl-2-(4-nitrophenyl)benzene

57.6 g (0.29 mol) of 1-bromo-4-nitrobenzene together with 50.0 g (0.37mol) of o-tolylboronic acid, 161 g (0.70 mol) of potassium phosphatetribasic monohydrate, 1.72 g (4.19 mmol) of2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl, and 314 mg (1.40 mmol)of palladium(II) acetate are suspended in 500 ml of toluene and 100 mlof water at room temperature under argon. The suspension is three timesevacuated and backfilled with argon, followed by heating under refluxfor two hours. The dark reaction mixture is cooled down to roomtemperature, diluted with toluene, and the resulting mixture two timesextracted with water. The organic phase is dried over magnesium sulfateand concentrated under vacuum. The resulting solid is recrystallizedfrom 2-propanol, giving the title product as an orange solid (yield:39.3 g (66%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=2.31 (s, 3H), 7.25-7.39 (m, 4H), 7.52-7.58(m, 2H), 8.27-8.33 (m, 2H).

b) Synthesis of 4-(o-tolyl)aniline

39.3 g (0.18 mol) of 1-methyl-2-(4-nitrophenyl)benzene and 2.25 g of 10wt %-palladium on carbon in 400 ml of ethanol are reacted in a pressurereactor under 2 bar hydrogen pressure at 35° C. during 5 hours. Thereaction mixture is cooled down to room temperature and the reactorflooded with argon. The reaction mixture is filtered through a layer ofHyflo® filter aid and rinsed with additional ethanol, followed by dryingunder vacuum. The residual oil is further purified by distillation undervacuum (0.3 mbar/140° C.), giving the title product as a beige solid(yield: 22.0 g (65%)).

¹H-NMR (300 MHz, CD₂Cl₂): δ=2.35 (s, 3H), 3.80 (br. s, 2H), 6.75-6.82(m, 2H), 7.15-7.21 (m, 2H), 7.24-7.35 (m, 4H).

c) Synthesis of N2,N3-bis[4-(o-tolyl)phenyl]quinoxaline-2,3-diamine

10.2 g (55.7 mmol) of 4-(o-tolyl)aniline and 6.40 g (66.6 mmol) ofsodium tert-butoxide in 100 ml of toluene are three times evacuated andbackfilled with argon. 135 mg (0.25 mmol) of BrettPhos ligand[=2-(dicyclohexylphosphino)3,6-dimethoxy-2′,4′,6′-triisopropyl-1,1′-biphenyl,CAS No. 1070663-78-3] and 201 mg (0.25 mmol) of BrettPhos-Pd-G3palladacycle{=[(2-dicyclohexylphosphino-3,6-dimethoxy-2′,4′,6′-triisopropyl-1,1′-biphenyl)-2-(2′-amino-1,1′-biphenyl)]palladium(II)methanesulfonate methanesulfonate, CAS No. 1470372-59-8} are added,followed by the addition of 5.00 g (25.1 mmol) of2,3-dichloroquinoxaline. The suspension is heated under reflux during 4hours, then cooled down to room temperature, and diluted with tolueneand water. The water phase is separated, and the organic phase two timesextracted with water. The organic phase is dried over magnesium sulfatefirst, then filtered, and the solution further filtered through a 4 cmlayer of silica gel, followed by rinsing the silica gel layer withtoluene. The combined eluents are concentrated under vacuum, and theresidual resin stirred in toluene first, followed by the addition ofhalf concentrated hydrochloric acid solution. Stirring is continueduntil a suspension is formed. The suspension is filtered, the solidwashed with heptane, and then further suspended in a mixture of heptaneand water. Concentrated aqueous sodium hydroxide solution is added untila basic pH is reached. The suspension is filtered, the solid washed withheptane, followed by drying under vacuum, giving the title product as abeige solid (yield: 1.68 g (14%)).

d) Synthesis of[3-[4-(o-tolyl)anilino]quinoxalin-2-yl]-[4-(o-tolyl)phenyl]ammoniumchloride

1.68 g (3.41 mmol) ofN2,N3-bis[4-(o-tolyl)phenyl]quinoxaline-2,3-diamine are treated with 50ml of concentrated aqueous hydrochloric acid and stirred at roomtemperature during 30 minutes. The orange suspension is carefullydiluted with 50 ml of water first, then filtered, and the solid driedunder vacuum, giving the title product as a yellow solid (2.3 gisolated, still including residual water).

e) Synthesis of2-ethoxy-1,3-bis[4-(o-tolyl)phenyl]-2H-imidazo[4,5-b]quinoxaline

2.3 g (max. 4.3 mmol, still including residual water) of[3-[4-(o-tolyl)anilino]quinoxalin-2-yl]-[4-(o-tolyl)phenyl]ammoniumchloride and 30 ml of triethyl orthoformate are heated under argon at100° C. during one hour in a reactor fitted with a Dean-Stark separatorand condenser. The reaction mixture is cooled down to room temperatureand concentrated under vacuum until a suspension formed. The suspensionis diluted with heptane, then filtered, and the solid dissolved indichloromethane. The solution is treated with ethanol, and concentratedunder vacuum until a suspension is formed. The suspension is filtered,the solid washed with ethanol, followed by drying under vacuum, givingthe title product as a yellow solid (yield: 1.70 g (minimum 71%)).

¹H-NMR (300 MHz, CD₂Cl₂): δ=1.16 (t, 3H), 2.40 (s, 6H), 3.49 (q, 2H),7.27-7.40 (m, 8H), 7.44-7.58 (m, 7H), 7.77-7.85 (m, 2H), 8.28-8.38 (m,4H).

f) Synthesis of Complex Intermediate (IX-a)

1.63 g (2.97 mmol) of2-ethoxy-1,3-bis[4-(o-tolyl)phenyl]-2H-imidazo[4,5-b]quinoxaline aredissolved under argon in 50 ml of o-xylene. 1.06 g (1.58 mmol) ofchloro(1,5-cyclooctadiene)-iridium(I) dimer are added and the resultingorange solution three times evacuated and backfilled with argon,followed by heating at 110° C. during two hours. The heating bath isremoved, the red solution treated with 50 ml of ethanol, followed byfurther cooling down to room temperature under stirring. The resultingorange suspension is further stirred during 30 minutes, then filtered,and the solid washed with 50 ml of ethanol. The solid is dissolved indichloromethane and filtered through a 2.5 cm layer of silica gel,followed by rinsing the silica gel layer with dichloromethane. Thecombined eluents are diluted with 150 ml of ethanol and concentratedunder vacuum until a suspension is formed. The suspension is filtered,the solid washed with ethanol, followed by drying under vacuum, givingthe title product as a yellow solid (yield: 0.95 g (38%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.44-1.56 (m, 2H), 1.57-1.76 (m, 4H),1.81-1.96 (m, 2H), 2.47 (s, 6H), 2.69-2.77 (m, 2H), 4.75-4.85 (m, 2H),7.33-7.48 (m, 8H), 7.64-7.72 (m, 4H), 7.81-7.88 (m, 2H), 8.15-8.22 (m,2H), 8.31-8.38 (m, 4H).

g) Synthesis of Complex (IX)

0.95 g (1.13 mmol) of complex intermediate (IX-a) and 1.67 g (4.53 mmol)of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are suspendedunder argon in 50 ml of o-xylene. The yellow suspension is three timesevacuated and backfilled with argon, followed by heating at 124° C.during two hours. The orange suspension is cooled down to roomtemperature, then concentrated under vacuum, and further purified bychromatography (silica gel, toluene/dichloromethane). The pure productfractions are concentrated under vacuum, and the resulting soliddissolved in dichloromethane, followed by the addition of ethanol. Thesolution is concentrated under vacuum until a suspension is formed. Thesuspension is filtered, the solid washed with ethanol, followed bydrying under vacuum, giving 0.7 g product. The solid is heated in 30 mlof DMF during one hour at 130° C. first, then at room temperature during30 minutes. The resulting suspension is filtered, the solid two timeswashed with ethanol, followed by drying under vacuum, giving the titleproduct as a yellow solid (yield: 0.5 g (33%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₇H₅₁IrN₁₂=1336.40; found1337.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.97 (s, 3H), 2.04 (s, 3H), 6.05 (d, 1H),6.16-8.04 (br. signal, 12H), 6.58-6.70 (m, 4H), 6.72 (d, 1H), 6.79-6.89(m, 2H), 6.90-6.96 (m, 1H), 6.99-7.07 (m, 2H), 7.09-7.15 (m, 3H),7.15-7.39 (m, 4H), 7.65-7.94 (m, 8H), 7.99 (dd, 1H), 8.27 (dd, 1H), 8.34(dd, 1H), 8.39 (dd, 1H), 9.03 (dd, 1H), 9.11-9.17 (m, 2H).

Synthesis Example 10 Synthesis of Complex (X) a) Synthesis ofN2,N3-bis(m-tolyl)quinoxaline-2,3-diamine

10.0 g (50.2 mmol) of 2,3-dichloroquinoxaline and 12.0 g (0.11 mol) ofm-toluidine in 70 ml of o-xylene are heated at 143° C. during one hour.The reaction mixture is cooled down to room temperature and treated witha small amount of 25% aqueous ammonia solution. The mixture is two timesextracted with 500 ml of water, and the organic phase dried overmagnesium sulfate and concentrated under vacuum. The dark brown oil isstirred at room temperature in 250 ml of heptane, and heated up to 40°C. The resulting suspension is stirred over an ice-bath during 15minutes. The beige suspension is filtered and the solid dissolved in 300ml of toluene, then treated with 10 ml of concentrated aqueoushydrochloric acid, and stirred at room temperature during 15 minutes.The suspension is filtered, the resulting solid washed with toluenefirst, followed by stirring in 250 ml of heptane and 50 ml of water. 30g of a 33% aqueous sodium hydroxide solution are added and the mixturestirred during one hour. The resulting suspension is filtered, the solidwashed with heptane, followed by drying under vacuum, giving the titleproduct as a light yellow solid (yield: 5.07 g (30%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=2.36 (s, 6H), 6.90 (d, 2H), 7.28 (t, 2H),7.34 (dd, 2H), 7.54 (dd, 2H), 7.74 (s, 2H), 7.81 (d, 2H), 9.16 (br. s,2H).

b) Synthesis of [3-(3-methylanilino)quinoxalin-2-yl]-(m-tolyl)ammoniumchloride

5.07 g (14.9 mmol) of[3-(3-methylanilino)quinoxalin-2-yl]-(m-tolyl)ammonium chloride aretreated with 25 ml of concentrated aqueous hydrochloric acid and stirredat room temperature during 20 minutes. 50 ml of water are added and thesuspension stirred during 10 minutes. The yellow suspension is filtered,the solid washed with a small amount of water, followed by drying undervacuum, giving the title compound as a yellow solid (4.57 g isolated,still including residual water).

¹H-NMR (400 MHz, d₆-DMSO): δ=2.37 (s, 6H), 7.01 (d, 2H), 7.33 (t, 2H),7.37 (dd, 2H), 7.61 (dd, 2H), 7.72-7.85 (m, 4H), 10.41 (br. s, 2H).

c) Synthesis of 2-ethoxy-1,3-bis(m-tolyl)-2H-imidazo[4,5-b]quinoxaline

4.57 g (max. 14.9 mmol, still including residual water) of[3-(3-methylanilino)quinoxalin-2-yl]-(m-tolyl)ammonium chloride and 75ml of triethyl orthoformate are heated under argon at 105° C. during onehour in a reactor fitted with a Dean-Stark separator and condenser. Theresulting solution is treated with a small amount of active charcoalfirst, and then cooled down under stirring until 40° C. are reached,followed by filtration over a 4 cm silica gel layer. The silica gellayer is rinsed with a small amount of ethanol and the combined eluentsconcentrated under vacuum. The resulting oil is stirred at roomtemperature in 50 ml of heptane until a solid is precipitating. Theresulting suspension is filtered, the solid washed with heptane,followed by drying under vacuum, giving the title product as a whitesolid (yield: 3.74 g (78%)).

¹H-NMR (300 MHz, d₆-DMSO): δ=0.89 (t, 3H), 2.42 (s, 6H), 3.25 (q, 2H),7.09 (d, 2H), 7.34-7.48 (m, 4H), 7.60-7.70 (m, 2H), 7.83 (s, 1H),7.92-8.06 (m, 4H).

d) Synthesis of Complex (X)

75 ml of o-xylene are three times evacuated and backfilled with argonand heated up to 130° C. 0.52 g (0.77 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer are added first and theorange suspension stirred during 5 minutes, followed by the addition of3.03 g (7.46 mmol) of2-ethoxy-1,3-bis(m-tolyl)-2H-imidazo[4,5-b]quinoxaline. The suspensionis heated under reflux during 17 hours, then cooled down to 80° C., andpoured into 300 ml of ethanol. The wine-red suspension is further cooleddown to room temperature, and stirring continued for one hour. Thesuspension is filtered, and the solid washed with ethanol. The solid isdissolved in 600 ml of dichloromethane, followed by the addition of 200ml of ethyl acetate, and concentration under vacuum until a suspensionis formed. The suspension is further stirred at room temperature during30 minutes, followed by filtration. The solid is washed with ethanol,followed by drying under vacuum, giving the title product as a yellowsolid (0.91 g (47%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₉H₅₁IrN₁₂=1240.40; found1241.5 [M+1]⁺.

Synthesis Example 11 Synthesis of Complex (XI) a) Synthesis of[3-(3-ethylanilino)quinoxalin-2-yl]-(3-ethylphenyl)ammonium chloride

3.05 g (15.3 mmol) of 2,3-dichloroquinoxaline and 4.10 g (33.8 mmol) of3-ethylaniline in 25 ml of o-xylene are heated at 122° C. during twohours. The resulting yellow thick suspension is cooled down to roomtemperature and treated with 100 ml of heptane. The mixture is furtherstirred under heating, then cooled down to room temperature and treatedwith 50 ml of 25% aqueous ammonia solution first, followed by theaddition of 300 ml of water together with 50 ml of heptane and 50 ml oftoluene, and further stirred at room temperature for 30 minutes. Theorganic phase is three times washed with 200 ml of water and treatedwith 30 ml of concentrated hydrochloric acid. The suspension isfiltered, the solid washed with heptane, followed by washing with a4:1-mixture of water and ethanol. The solid is further dried undervacuum, giving the title product as a slightly yellow solid (5.9 gisolated, still including residual water).

¹H-NMR (300 MHz, d₆-DMSO): δ=1.25 (t, 6H), 2.67 (q, 4H), 6.97-7.05 (m,2H), 7.29-7.43 (m, 4H), 7.54-7.63 (m, 2H), 7.74-7.86 (m, 4H), 10.12 (br.s, 2H).

b) Synthesis of2-ethoxy-1,3-bis(3-ethylphenyl)-2H-imidazo[4,5-b]quinoxaline

A yellow suspension of 5.9 g (max. 14.6 mmol, still including residualwater) of [3-(3-ethyl-anilino)quinoxalin-2-yl]-(3-ethylphenyl)ammoniumchloride and 50 g (0.34 mol) of triethyl orthoformate is heated in areactor fitted with a Dean-Stark separator and condenser under argon at80° C. during two hours first, and at 100° C. during one hour. Thereaction solution is concentrated under vacuum. The residual oil isstirred together with 25 ml of heptane during 10 minutes. The resultingsuspension is filtered, the solid washed with a small amount of heptane,followed by drying under vacuum, giving the title product as ablueish-white solid (yield: 3.54 g (min. 57%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.90 (t, 3H), 1.27 (t, 6H), 2.27 (q, 4H),3.27 (q, 2H), 7.09-7.17 (m, 2H), 7.35-7.48 (2 m, 4H), 7.60-7.67 (m, 2H),7.85 (s, 1H), 7.97-8.06 (m, 4H).

c) Synthesis of Complex (XI)

50 ml of o-xylene are three times evacuated and backfilled with argonand heated up to 132° C. A slightly turbid orange solution of 2.95 g(6.95 mmol) of2-ethoxy-1,3-bis(3-ethylphenyl)-2H-imidazo[4,5-b]quinoxaline and 0.59 g(0.88 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer is added,using an additional portion of pre-heated o-xylene (total 20 ml) forrinsing the flask for complete transfer of the reagents. The resultingdark red solution is heated at 143° C. during 17 hours. The darkreaction solution is cooled down to 110° C. and poured onto 300 ml ofethanol. The red suspension is stirred until a temperature of 32° C. isreached. The suspension is filtered, the solid washed with ethanol,followed by drying under vacuum. The solid is dissolved indichloromethane and filtered through a 4 cm layer of silica gel,followed by rinsing the silica gel layer with dichloromethane and amixture of dichloromethane/ethanol. The combined fractions are dilutedwith 100 ml of ethanol and concentrated under vacuum, until a suspensionformed. The suspension is further stirred at room temperature, thenfiltered, the solid washed with ethanol, followed by drying undervacuum, giving the title product as a yellow solid (yield: 1.42 g(61%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₅H₆₃IrN₁₂=1324.49; found1325.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.65-1.40 (br. signal, 9H), 1.36 (t, 9H),1.89-2.91 (br. signal, 6H), 2.67-2.87 (m, 6H), 5.98-7.67 (br. signal,12H), 6.55 (d, 3H), 6.71 (d, 3H), 7.75 (t, 3H), 7.84 (t, 3H), 7.92 (d,3H), 8.34 (d, 3H), 8.89 (br. s, 3H).

Synthesis Example 12 Synthesis of Complex (XII) a) Synthesis ofN2,N3-bis(3,4-dimethylphenyl)quinoxaline-2,3-diamine

20.0 g (0.10 mol) of 2,3-dichloroquinoxaline and 28.0 g (0.23 mol)3,4-dimethylaniline in 400 ml of o-xylene are heated at 140° C. during23 hours. 28.0 g of 3,4-dimethylaniline are added and heating continuedat the same temperature during 19 hours. The yellow suspension is cooleddown to room temperature and diluted with 200 ml of heptane. Thesuspension is filtered and the solid stirred in 500 ml of heptane,followed by filtration. The solid is stirred in 500 ml of water togetherwith 100 ml of 25% aqueous ammonia solution and 250 ml heptane. Thesuspension is filtered, followed by stirring the solid in 500 ml ofheptane, and then by stirring the solid in methanol (2× 500 ml). Thesuspension is filtered, the solid dried under vacuum giving the titleproduct as a light yellow solid (yield: 36.6 g (99%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=2.26 (s, 6H), 2.28 (s, 6H), 7.21 (d, 2H),7.31-7.39 (m, 2H), 7.55-7.62 (m, 2H), 7.62-7.72 (m, 4H), 10.22 (br. s,2H).

b) Synthesis of[3-(3,4-dimethylanilino)quinoxalin-2-yl]-(3,4-dimethylphenyl)ammoniumchloride

36.6 g (0.10 mol) ofN2,N3-bis(3,4-dimethylphenyl)quinoxaline-2,3-diamine are added inseveral portions to 350 ml of concentrated hydrochloric acid and stirredat room temperature during one hour. The reaction mixture is filteredand the solid dried under vacuum, followed by two times stirring incyclohexane. The suspension is filtered, followed by drying the solidunder vacuum, giving the title product as a light yellow solid (41.9 gisolated, sill including residual water).

¹H-NMR (400 MHz, d₆-DMSO): δ=2.27 (s, 6H), 2.28 (s, 6H), 7.25 (d, 2H),7.34-7.43 (m, 2H), 7.58-7.73 (m, 6H), 11.42 (br. s, 2H).

c) Synthesis of1,3-bis(3,4-dimethylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxaline

40.2 g (max. 0.1 mol, still including residual water) of[3-(3,4-dimethylanilino)quinoxalin-2-yl]-(3,4-dimethylphenyl)ammoniumchloride and 350 ml of triethyl orthoformate are heated under argon at95° C. during 30 minutes in a reactor fitted with a Dean-Stark separatorand condenser. The reaction mixture is cooled down to room temperatureand treated with 1.2 g of active charcoal, followed by stirring at 110°C. during 30 minutes. The mixture is cooled down and filtered over a 3cm layer of Hyflo® filter aid, followed by rinsing the filter aid with150 ml of ethanol. After short time precipitation of a solid is startingin the combined filtrates, providing a white suspension. The suspensionis stirred at room temperature during 30 minutes, followed byfiltration, and rinsing the solid with 50 ml of ethanol. The solid isfurther dried under vacuum, and then mixed with 250 ml of cyclohexaneand 150 ml of dichloromethane. The suspension is heated up to 50° C. andthe resulting light yellow solution concentrated under vacuum until mostof dichloromethane is evaporated off. The residual solution is cooleddown to room temperature and the resulting suspension filtered. Thesolid is washed with a small amount of cyclohexane, followed by dryingunder vacuum, giving the title compound as a white solid (yield: 36.2 g(min. 86%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.89 (t, 3H), 2.28 (s, 6H), 2.33 (s, 6H),3.25 (q, 2H), 7.29 (d, 2H), 7.36 (m, 2H), 7.61 (m, 2H), 7.78 (s, 1H),7.83-7.93 (m, 4H).

d) Synthesis of Complex (XII)

75 ml of o-xylene are three times evacuated and backfilled with argonand heated up to 135° C. A slightly turbid orange solution of 6.00 g(14.1 mmol) of1,3-bis(3,4-dimethylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxaline and1.19 g (1.77 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer isadded, using an additional portion of pre-heated o-xylene (total 20 ml)for rinsing the flask for complete transfer of the reagents. Theresulting reaction mixture is heated at 132° C. during 17 hours. Thedark reaction solution is cooled down to 120° C. and poured onto 1.2 Lof ethanol. The orange-yellow suspension is stirred until 35° C. arereached. The yellow suspension is filtered and the solid washed withethanol. The solid is suspended in 200 ml of ethanol and heated underreflux during one hour. The suspension is cooled down to roomtemperature and filtered, the solid washed with ethanol, followed bydrying. The solid is suspended in toluene and heated under reflux. Thesolution is cooled down to 9° C. and the solid filtered off, and washedwith a small amount of toluene. The solid is further purified bychromatography (silica gel, dichloromethane/heptane), giving the titleproduct as a yellow solid (yield: 1.78 g (38%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₅H₆₃IrN₁₂=1324.49; found1325.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.25 (br. s, 9H), 1.48-2.36 (br. signal,9H), 2.05 (s, 9H), 2.41 (s, 9H), 5.84-7.67 (br. signal, 12H), 7.67-7.98(m, 9H), 8.35 (d, 3H), 8.78 (s, 3H).

Synthesis Example 13 Synthesis of Complex (XIII) a) Synthesis ofN2,N3-bis(4-tert-butylphenyl)pyrazine-2,3-diamine

71.3 g 4-tert-butyl aniline (0.47 mol) are added to a solution of2,3-dichloropyrazine (32.3 g; 0.21 mol) in 200 ml o-xylene. The redsolution is heated to 150° C. over 1.25 hours and stirred at thattemperature overnight. The mixture turns to a brownish yellowsuspension. After cooling to room temperature, the yellow solid isfiltered and washed with successive portions of heptane, aqueoussaturated sodium bicarbonate, and ethanol. The product is dried undervacuum at 60° C. to give the title product as a bright yellow solid(yield: 52.5 g (66%)).

¹H-NMR (300 MHz, d₆-DMSO): δ=8.91 (br.s, 2H), 7.59 (m, 4H), 7.48 (s, 2H)7.36 (m, 4H), 1.29 (s, 18H).

b) Synthesis of1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]pyrazine

17.1 g (45.7 mmol) of N2,N3-bis(4-tert-butylphenyl)pyrazine-2,3-diamineand 67.7 g (0.46 mol) of triethylothoformate are heated in a 3-neckedflask fitted with a Dean-Stark separator and condenser to 130° C. (bathtemperature). Distillation of a ethanol/triethylorthoformate mixturestarts at ca. 105° C. internal temperature. After 105 minutes (int.temperature 120° C.), distillation ceases and the suspension is filteredat ca. 80° C. in order to remove some residual solid. The filtrate isconcentrated under vacuum to give 17 g of pink crude product, which isrecrystallized from 35 g heptane to give the title compound as a lightpinkish solid (yield: 13.0 g (66%)).

¹H-NMR (400 MHz, CDCl₃): δ=7.94-7.89 (m, 4H), 7.52 (s, 2H), 7.51-7.47(m, 4H), 7.21 (s, 1H), 3.38 (q, J=7.0 Hz, 2H), 1.37 (s, 18H), 1.13 (t,J=7.0 Hz, 3H).

c) Synthesis of Complex Intermediate (XIII-a)

3.90 g (5.81 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended in 70 ml of toluene and three times evacuated and backfilledwith argon, and heated up to 73° C. A solution of 5.00 g (11.6 mmol) of1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]pyrazine in 70 mlof toluene is added within 45 minutes and the resulting greenish-brownsolution heated at 74° C. during 17 hours. The warm reaction mixture isfiltered, the solid washed with toluene and heptane, followed by dryingunder vacuum, giving the title product as a brownish-yellow solid(yield: 6.83 g (82%)).

¹H-NMR (400 MHz, CDCl₃): δ=1.25-1.49 (2 m, 4H), 1.44 (s, 18H), 1.49-1.62(m, 2H), 1.67-1.81 (m, 2H), 2.45-2.55 (m, 2H), 4.63-4.74 (m, 2H), 7.65(d, 4H), 8.07 (d, 4H), 8.32 (s, 2H).

d) Synthesis of Complex (XIII)

2.00 g (2.78 mmol) of complex intermediate (XIII-a) and 2.05 g (5.56mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aresuspended under argon in 40 ml of 1,2-dichlorobenzene. The yellowsuspension is three times evacuated and backfilled with argon, followedby heating at 116° C. during seven hours. The dark solution is cooleddown to room temperature, diluted with 100 ml of heptane and filtered.The solid is washed with ethanol. The combined filtrates areconcentrated under vacuum and the residue subjected to furtherpurification by chromatography (silica gel, dichloromethane/heptane),giving the title product as a yellow solid (yield: 0.64 g (19%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₇H₅₃IrN₁₂=1218.41; found1219.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.69 (s, 9H), 1.06 (s, 9H), 5.99-7.99 (br.signal, 10H), 6.54 (br. d, 2H), 6.61-6.69 (m, 2H), 6.69-6.75 (m, 2H),6.85-6.97 (m, 3H), 7.18-7.33 (m, 3H), 7.69-7.78 (m, 2H), 7.79-7.87 (m,2H), 7.87-7.93 (m, 1H), 8.11 (d, 1H), 8.31-8.37 (m, 2H), 8.38 (d, 1H),8.67 (d, 1H), 9.08 (d, 1H), 9.15 (d, 1H).

Synthesis Example 14 Synthesis of Complex (XIV) a) Synthesis of[3-(3-ethylanilino)pyrazin-2-yl]-(3-ethylphenyl)ammonium chloride

13.3 g (8.93 mmol) of 2,3-dichloropyrazine and 25 ml (0.2 mol) of3-ethylaniline in 30 ml of o-xylene are heated under reflux during 20hours. The dark reaction mixture is cooled down to room temperature andpoured onto 300 ml of 10% aqueous hydrochloric acid solution, followedby the addition of 200 ml of heptane, and stirring for one hour. Thesuspension is filtered and the solid washed with water and heptane,followed by drying under vacuum. The solid is suspended in 1 L of 10%aqueous sodium hydroxide and 1 L of heptane, followed by stirring during30 minutes and filtration. The solid is washed with water and heptane,and then stirred in 500 ml of 10% aqueous hydrochloric acid and 400 mlof heptane during 30 minutes. The suspension is filtered and the solidwashed with water and further dried under vacuum giving the titleproduct as a white solid (28.5 g isolated, still including residualwater).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.21 (t, 6H), 2.62 (q, 4H), 6.95 (d, 2H),7.28 (t, 2H), 7.49 (s, 2H), 7.53 (s, 2H), 7.58 (d, 2H), 9.68 (br. s,2H).

b) Synthesis of2-ethoxy-1,3-bis(3-ethylphenyl)-2H-imidazo[4,5-b]pyrazine

27.0 g (max. 76 mmol, still including residual water) of[3-(3-ethylanilino)pyrazin-2-yl]-(3-ethylphenyl)ammonium chloride and200 ml (1.2 mol) of triethyl orthoformate are heated under argon at 130°C. during five hours in a reactor fitted with a Dean-Stark separator andcondenser. The reaction solution is concentrated under vacuum and dried,giving the title compound as a yellowish solid (yield: 22.2 g (78%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.90 (t, 3H), 1.23 (t, 6H), 2.66 (q, 4H),3.18 (q, 2H), 7.03 (d, 2H), 7.36 (t, 2H), 7.51 (s, 2H), 7.72 (s, 1H),7.84-7.94 (m, 4H).

c) Synthesis of Complex Intermediate (XIV-a)

3.68 g (5.48 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer aresuspended in 50 ml of toluene and three times evacuated and backfilledwith argon, and heated up to 73° C. A solution of 4.10 g (10.9 mmol) of2-ethoxy-1,3-bis(3-ethylphenyl)-2H-imidazo[4,5-b]pyrazine in 50 ml oftoluene is slowly added and the resulting greenish-brown solution heatedat 74° C. during one hour. The orange-brown slightly turbid solution isfiltered and the filtrate diluted with 100 ml of ethanol and cooled downusing an ice-bath. The resulting suspension is filtered and the solidwashed with ethanol and heptane, followed by drying under vacuum, givingthe title product as a yellow solid (yield: 4.10 g (56%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.28-1.66 (m, 6H), 1.40 (t, 6H), 1.69-1.87(m, 2H), 2.54-2.64 (m, 2H), 2.78-2.93 (m, 4H), 4.56-4.67 (m, 2H),7.42-7.49 (m, 2H), 7.55 (t, 2H), 7.79-7.87 (m, 2H), 8.16-8.22 (m, 2H),8.32 (s, 2H).

d) Synthesis of Complex (XIV)

2.00 g (3.0 mmol) of complex intermediate (XIV-a) and 2.18 g (6.0 mmol)of the 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are suspendedin 100 ml of o-xylene, and heated at 144° C. during 18 hours. The darksolution is cooled down to room temperature, diluted with 150 ml ofethanol, and further cooled down with an ice-bath. The suspension isfiltered, the solid washed with ethanol, followed by drying undervacuum. The solid is dissolved in 1 L of dichloromethane and thesolution filtered through a 4 cm layer of silica gel, followed byrinsing the silica gel layer with 500 ml of dichloromethane. Thecombined fractions are mixed with 50 ml of ethanol and the solutionconcentrated under vacuum until a solid formed. The solid is filteredoff and dissolved in 1 L of dichloromethane, then filtered and thefiltrate treated with 50 ml of ethyl acetate. The solution isconcentrated under vacuum to a volume of 250 ml, and the resultingsuspension filtered. The solid is washed with ethyl acetate and driedunder vacuum, giving the title product as a yellow solid (yield: 0.36 g(10%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₃H₄₅IrN₁₂=1162.35; found1163.5 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.22-1.36 (m, 6H), 2.73 (q, 4H), 6.00-7.98(br. signal, 12H), 6.55 (d, 1H), 6.58-6.66 (m, 1H), 6.66-6.76 (m, 3H),6.81-6.96 (m, 3H), 7.21-7.32 (m, 2H), 7.77-7.80 (m, 2H), 7.80-7.95 (m,4H), 8.11 (d, 1H), 8.26-8.42 (m, 3H), 8.70 (s, 1H), 9.01-9.12 (m, 2H).

Synthesis Example 15 Synthesis of Complex (XV) a) Synthesis ofN2,N3-bis(m-tolyl)pyrazine-2,3-diamine

A solution of 13.8 g 2,3-dichloropyrazine (92.6 mmol) in 100 gm-toluidine (0.93 mol) is heated at 140° C. for five hours. The mixtureis allowed to cool to 50° C. and diluted with 150 ml methanol. It isfurther cooled in an ice bath whereby products starts to precipitate.After stirring at room temperature overnight, the mixture is cooledagain to 10° C. and the light beige suspension is filtered. The crudeproduct is resuspended in 100 ml cold methanol, filtered, and driedunder vacuum to give the title product as a light beige solid (yield:19.2 g (71.6%)).

¹H-NMR (300 MHz, d₆-DMSO): δ=8.93 (bs, 2H), 7.71-7.41 (m, 6H), 7.27-7.09(m, 2H), 6.88-6.72 (m, 2H), 2.30 (s, 6H).

b) Synthesis of [3-(3-methylanilino)pyrazin-2-yl]-(m-tolyl)ammoniumchloride

A yellow suspension of 19 g (65 mmol) ofN2,N3-bis(m-tolyl)pyrazine-2,3-diamine in 400 ml of ethanol and 128 g of37% hydrochloric acid is stirred at room temperature overnight. Theproduct is filtered, washed with heptane (3×100 ml), and dried undervacuum. The product is obtained as a yellow solid (17.9 g isolated,still including residual water).

¹H-NMR (300 MHz, d₆-DMSO): δ=10.07 (bs, 2H), 7.69-7.52 (m, 4H), 7.48 (s,2H), 7.31-7.14 (m, 2H), 6.91 (dt, J=6.8, 1.2 Hz, 2H), 6.7 (bs, 1H), 2.32(s, 6H).

c) Synthesis of 2-ethoxy-1,3-bis(m-tolyl)-2H-imidazo[4,5-b]pyrazine

17.8 g of [3-(3-methylanilino)pyrazin-2-yl]-(m-tolyl)ammonium chloride(max. 55 mmol, still including residual water) are suspended in 207 gtriethyl orthoformate (1.36 mol) are heated at 110° C. for six hours ina reactor fitted with a Dean-Stark separator and condenser. 14 ml ofethanol and triethylorthoformate are separated during the reaction time.The reaction mixture is cooled, filtered, and the orange filtrate isconcentrated under vacuum. The crude product is washed with ethanol andheptane, filtered, purified by resuspension in ethanol (3×), and driedunder vacuum. The title compound is obtained as a salmon pink powder(yield: 10.8 g (57%)).

¹H-NMR (300 MHz, d₆-DMSO): δ=7.89 (m, 2H), 7.85 (m, 2H), 7.75 (s, 1H),7.52 (s, 2H), 7.36 (t, 2H), 7.02 (m, 2H), 3.18 (q, J=7.0 Hz, 2H), 2.38(s, 6H), 0.91 (t, J=7.0 Hz, 3H).

d) Synthesis of Complex Intermediate (XV-a)

3.00 g (4.47 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer and3.09 g (8.92 mmol) of2-ethoxy-1,3-bis(m-tolyl)-2H-imidazo[4,5-b]pyrazine are dissolved in 50ml of toluene. The dark solution is three times evacuated and backfilledwith argon, and heated at 75° C. during two hours. The reaction mixtureis cooled down to room temperature and diluted with 100 ml of ethanol.The resulting suspension is filtered, the solid washed with ethanol andheptane, followed by drying under vacuum, giving the title product as ayellow solid (yield: 3.88 g (68%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.33-1.45 (m, 2H), 1.47-1.66 (m, 4H),1.75-1.88 (m, 2H), 2.55 (s, 6H), 2.58-2.65 (m, 2H), 4.59-4.67 (m, 2H),7.43 (d, 2H), 7.53 (t, 2H), 7.92 (d, 2H), 8.06 (s, 2H), 8.33 (s, 2H).

e) Synthesis of Complex (XV)

2.00 g (3.14 mmol) of complex intermediate (XV-a) and 4.63 g (12.6 mmol)of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are dissolvedunder argon in 40 ml of chlorobenzene. The yellow solution is threetimes evacuated and backfilled with argon, followed by heating at 124°C. during 23 hours. The reaction mixture is cooled down to roomtemperature and treated with 40 ml of ethanol and 80 ml of acetone,followed by stirring during 30 minutes. The suspension is filtered, andthe solid washed with 30 ml of ethanol first, followed by washing with30 ml of acetone and 30 ml of heptane. The solid is dried under vacuumand further purified by chromatography (silica gel,dichloromethane/heptane), giving the title product as a yellow solid(yield: 1.94 g (54%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₁H₄₁IrN₁₂=1134.32; found1135.3 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.61-2.67 (br. signals, 3H), 2.43 (s, 3H),5.86-7.69 (br. signals, 12H), 6.53 (d, 1H), 6.59-6.76 (m, 5H), 6.82-6.92(m, 2H), 7.21-7.33 (m, 2H), 7.70-7.96 (m, 6H), 8.10 (d, 1H), 8.26-8.42(m, 3H), 8.67 (s, 1H), 9.00-9.14 (m, 2H).

Synthesis Example 16 Synthesis of Complex (XVI)

1.50 g (2.47 mmol) of complex intermediate (II-1) and 2.38 g (4.95 mmol)of 1,3-bis(4-tert-butyl-phenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxalineare suspended under argon in 70 ml of o-xylene. The grey-yellowsuspension is three times evacuated and backfilled with argon, followedby heating at 128° C. during 20 hours. The reaction mixture is cooleddown to room temperature and concentrated under vacuum. The residue isdissolved in dichloromethane and filtered through a 4 cm layer of silicagel followed by rinsing the silica gel layer with dichloromethane. Thecombined eluents are concentrated under vacuum and the solid furtherpurified by chromatography (silica gel, heptane/ethyl acetate). Theisolated product is dissolved in dichloromethane first, followed by theaddition of 20 ml of ethanol. The solution is concentrated until asuspension is formed. The suspension is filtered, the solid washed withethanol and further dried under vacuum, giving a first crop of the titleproduct as a yellow solid. The filtrate is concentrated giving a secondcrop of the title product (combined yield: 0.45 g (14%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₅H₆₉IrN₁₂=1330.54; found1331.7 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.76 (s, 9H), 1.08 (2 s, 18H), 1.10 (s, 9H),6.10-7.68 (br. signal, 12H), 6.60-6.73 (m, 4H), 6.87 (t, 1H), 7.18-7.30(m, 3H), 7.69-7.78 (m, 2H), 7.79-7.93 (m, 4H), 8.09 (d, 1H), 8.30-8.38(m, 2H), 8.39 (d, 1H), 8.86-8.93 (m, 2H), 8.90 (d, 1H).

Synthesis Example 17 Synthesis of Complex (XVII) a) Synthesis ofN2,N3-bis(4-phenylphenyl)pyrazine-2,3-diamine

25.0 g (0.15 mol) of 4-biphenylamine and 16.8 g (0.17 mol) of sodiumtert-butoxide in 200 ml of toluene are three times evacuated andbackfilled with argon. 0.36 g (0.67 mmol) of BrettPhos ligand[=2-(dicyclohexylphosphino)3,6-dimethoxy-2′,4′,6′-triisopropyl-1,1′-biphenyl,CAS No. 1070663-78-3] and 0.54 g (0.68 mmol) of BrettPhos-Pd-G3palladacycle{=[(2-di-cyclohexylphosphino-3,6-dimethoxy-2′,4′,6′-triisopropyl-1,1′-biphenyl)-2-(2′-amino-1,1′-biphenyl)]palladium(II)methanesulfonate methanesulfonate, CAS No. 1470372-59-8} are added,followed by the addition of 10.2 g (68.5 mmol) of 2,3-dichloropyrazine.The temperature is raised up to 85° C. during which a thick suspensionis formed. Heating is continued at 85° C. during 20 hours. The reactionmixture is cooled down to room temperature, filtered, and the solidrinsed with toluene. The yellow solid is suspended first in 300 ml ofheptane, then filtered, followed by stirring the resulting solid in 150ml of ethanol under reflux. The hot suspension is filtered and the solidwashed with ethanol. The solid is stirred in solution of 150 ml of waterand 1.5 g of sodium cyanide under moderate heating. The suspension isfiltered, the solid washed with water and heated up again in 150 ml ofethanol. The hot suspension is filtered, the solid dried under vacuum,giving the title product as a light yellow solid (yield: 18.1 g (65%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.33 (t, 2H), 7.46 (t, 4H), 7.60-7.73 (m,10H), 7.80 (d, 4H), 8.70 (s, 2H).

b) Synthesis of[3-(4-phenylanilino)pyrazin-2-yl]-(4-phenylphenyl)ammonium chloride

A yellow suspension of 18.1 g (43.6 mmol) ofN2,N3-bis(4-phenylphenyl)pyrazine-2,3-diamine and 120 ml of concentratedhydrochloric acid is stirred at room temperature during 15 minutes. 100ml of water are carefully added under stirring and the resultingsuspension filtered, and the solid dried under vacuum, giving the titleproduct as a light yellow solid (32.6 g isolated, still includingresidual water).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.34 (t, 2H), 7.47 (t, 4H), 7.55 (s, 2H),7.63-7.77 (m, 8H), 7.91 (d, 4H), 10.21 (br. s, 2H).

c) Synthesis of2-ethoxy-1,3-bis(4-phenylphenyl)-2H-imidazo[4,5-b]pyrazine

20.4 g (max. 45 mmol, still including residual water) of[3-(4-phenylanilino)pyrazin-2-yl]-(4-phenylphenyl)ammonium chloride aresuspended in 200 ml of triethyl orthoformate and heated at 110° C.during 17 hours in a reactor fitted with a Dean-Stark separator andcondenser. The orange-brown slightly turbid solution is cooled down andfiltered through a 2 cm layer of silica gel, followed by rinsing thesilica gel layer with heptane and ethanol. The combined eluents arefiltered over cellulose powder, followed by rinsing the cellulose powderwith heptane. The combined eluents are concentrated under vacuum until asuspension is formed. The suspension is further stirred at roomtemperature, then filtered, and the solid washed with ethanol, followedby drying under vacuum. The solid is dissolved in dichloromethanefollowed by addition of ethanol. The solution is concentrated undervacuum until a suspension is formed. The suspension is cooled down toroom temperature under stirring, then filtered, and the solid washedwith ethanol, followed by drying under vacuum, giving the title productas a light pink solid (yield: 11.2 g (minimum 53%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.95 (t, 3H), 3.24 (q, 2H), 7.37 (t, 2H),7.49 (t, 4H), 7.59 (s, 2H), 7.73 (d, 4H), 7.82 (d, 4H), 7.90 (s, 1H),8.19 (d, 4H).

d) Synthesis of Complex Intermediate (XVII-a)

4.32 g (6.43 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer and6.02 g (12.8 mmol) of2-ethoxy-1,3-bis(4-phenylphenyl)-2H-imidazo[4,5-b]pyrazine are dissolvedin 250 ml of toluene. The orange slightly turbid solution is three timesevacuated and backfilled with argon, and heated under reflux during onehour. The hot hot orange suspension is filtered through a 3 cm layer ofsilica gel and the silica gel layer rinsed two times with 25 ml oftoluene. The solid is dried under vacuum, giving the title product as ayellow solid (yield: 7.9 g (81%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.36-1.47 (m, 2H), 1.51-1.68 (m, 4H),1.77-1.92 (m, 2H), 2.67 (m, 2H), 4.71 (m, 2H), 7.44-7.51 (m, 2H),7.52-7.61 (m, 4H), 7.77-7.83 (m, 4H), 7.88-7.95 (m, 4H), 8.26-8.33 (m,4H), 8.37 (s, 2H).

e) Synthesis of Complex (XVII)

50 ml of o-xylene are three times evacuated and backfilled with argonand heated up to 132° C. 0.80 g (1.05 mmol) of complex intermediate(XVII-a) and 0.81 g (2.20 mmol) of2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are added andstirring continued at 134° C. during one hour. The dark red suspensionis cooled down to room temperature followed by filtration. The solid iswashed with o-xylene. The filtrate is treated with 200 ml of ethanol andthe resulting suspension stirred during 10 minutes, followed byfiltration. The filtrate is filtered over a 0.5 cm layer of Hyflo®filter aid, followed by rinsing the filter aid with dichloromethane. Thecombined filtrates are concentrated under vacuum. The resulting solid isfurther purified by chromatography (silica gel,dichloromethane/heptane). The isolated product fractions areconcentrated under vacuum and the solid dissolved in a minimal amount ofdichloromethane followed by the addition of 50 ml of ethanol. Thesolution is concentrated under vacuum until a suspension is formed. Thesuspension is further stirred at room temperature, then filtered, andthe solid washed with ethanol, followed by drying under vacuum, givingthe title product as a light yellow solid (190 mg (14%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₁H₄₅IrN₁₂=1258.35; found1259.5 [M+1]⁺.

¹H-NMR (300 MHz, CD₂Cl₂): δ=6.16-7.96 (br. signal, 12H), 6.59-6.69 (m,3H), 6.76-6.86 (m, 3H), 6.88-7.03 (m, 5H), 7.07-7.15 (m, 1H), 7.16-7.24(m, 1H), 7.25-7.40 (m, 6H), 7.46-7.53 (dd, 1H), 7.59-7.87 (m, 5H),7.87-7.93 (m, 1H), 8.16 (d, 1H), 8.28-8.37 (m, 2H), 8.42 (d, 1H), 8.87(d, 1H), 9.08-9.19 (m, 2H).

Synthesis Example 18 Synthesis of Complex (XVIII)

3.50 g (5.31 mmol) of complex intermediate (VIII-a) and 3.38 g (10.6mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]pyrazine (see synthesisexample 16, WO2011/073149) are dissolved under argon in 70 ml ofchlorobenzene. The reaction mixture is three times evacuated andbackfilled with argon, followed by heating at 112° C. during 18 hours.The reaction mixture is cooled down to room temperature, treated with400 ml of ethanol and vigorously stirred during 30 minutes. Thesuspension is filtered, and the solid subjected to further purificationby chromography (silica gel, dichloromethane/ethyl acetate), giving thetitle product as a yellow solid (yield: 1.53 g (27%)).

APCI-LC-MS (positive, m/z): exact mass of C₅₅H₃₅IrN₁₂=1056.27; found1057.4 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.12-8.06 (br. signal, 12H), 6.61 (t, 1H),6.67-6.75 (m, 3H), 6.82-6.95 (m, 5H), 7.17-7.32 (m, 3H), 7.71-7.79 (m,1H), 7.80-7.93 (m, 2H), 8.07-8.15 (m, 2H), 8.30-8.43 (m, 3H), 8.82 (t,2H), 9.09 (d, 1H).

Synthesis Example 19 Synthesis of Complex (XIX)

2.50 g (3.80 mmol) of complex intermediate (VIII-a) and 3.27 g (7.59mmol) of 1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]pyrazineare suspended under argon in 100 ml of toluene. The yellow suspension isthree times evacuated and backfilled with argon, followed by heating at108° C. during 22 hours. The reaction mixture is cooled down to roomtemperature and diluted with 400 ml of heptane, followed by stirringduring one hour. The suspension is filtered and the solid washed withheptane. The combined filtrates are concentrated under vacuum and thesolid further purified by chromatography (silica gel,dichloromethane/heptane), giving the title product as a yellow solid(yield: 1.40 g (28%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₁H₆₇IrN₁₂=1280.52; found1281.7 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.73 (s, 9H), 1.08 (s, 27H), 5.92-7.93 (br.signal, 12H), 6.61 (d, 1H), 6.64 (d, 1H), 6.76 (d, 1H), 6.88 (t, 1H),6.97 (t, 1H), 7.18-7.30 (m, 3H), 7.66-7.74 (m, 1H), 7.77-7.88 (m, 2H),8.06-8.13 (m, 2H), 8.33 (d, 1H), 8.38 (dd, 2H), 8.67 (d, 1H), 8.72 (d,1H), 9.11 (d, 1H).

Synthesis Example 20 Synthesis of Complex (XX) a) Synthesis of ComplexIntermediate (XX-a)

5.00 g (14.0 mmol) of 1,3-diphenylbenzimidazol-3-ium tetrafluoroborate(see synthesis in WO2005/019373) are suspended in 80 ml of toluene andcooled down to −10° C. 27.9 ml (14.0 mmol) of potassiumbis(trimethylsilyl)amide solution (KHMDS, 0.5M in toluene) are addedwithin 10 minutes at a maximum temperature of −8° C. The cooling bath isremoved and the suspension stirred during 40 minutes reaching roomtemperature. The greenish suspension is added within 15 minutes to apreheated brownish solution of 4.69 g (7.0 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer in 120 ml of toluene at 74°C., and stirring continued at the same temperature during three hours.The warm suspension is filtered through a 3 cm layer of silica gel andthe silica gel layer rinsed with toluene. The collected fractions areconcentrated under vacuum and the resulting solid dissolved in a minimalamount of dichloromethane, followed by the addition of 50 ml of ethanol.The solution is concentrated until a suspension is generated. Thesuspension is filtered, the solid washed with cold ethanol and driedunder vacuum, giving the title compound as a yellow solid (yield: 6.20 g(74%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.22-1.36 (m, 2H), 1.39-1.54 (m, 4H),1.66-1.82 (m, 2H), 2.52-2.62 (m, 2H), 4.39-4.49 (m, 2H), 7.28-7.40 (2 m,4H), 7.57-7.70 (m, 6H), 8.04-8.13 (m, 4H).

b) Synthesis of Complex (XX)

8.00 g (13.2 mmol) of complex intermediate (XX-a) and 19.5 g (52.8 mmol)of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are dissolvedunder argon in 120 ml of chlorobenzene. The yellow solution is threetimes evacuated and backfilled with argon, followed by heating at 124°C. during 21 hours. The reaction mixture is cooled down to roomtemperature and treated with 100 ml of ethanol and 300 ml of acetone,followed by stirring during 30 minutes. The suspension is filtered, thesolid washed with 100 ml of ethanol first, followed by washing with 100ml of acetone and 100 ml of heptane. The collected filtrates areconcentrated under vacuum and further purified by chromatography (silicagel, dichloromethane/heptane). The pure product fractions are collectedand concentrated under vacuum, until a suspension is formed. Thesuspension is filtered, the solid washed with 100 ml of ethanol and 100ml of heptane, followed by drying under vacuum, giving the title productas a yellow solid (yield: 5.10 g (35%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₁H₃₉IrN₁₀=1104.30; found1105.2 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=5.92-7.68 (br. signal, 8H), 6.32-6.41 (m,2H), 6.47-6.67 (m, 5H), 6.67-6.76 (t, 2H), 6.78-6.92 (m, 4H), 7.13 (t,1H), 7.17-7.30 (m, 3H), 7.30-7.44 (m, 2H), 7.69-7.94 (2 m, 6H), 8.06 (d,1H), 8.22 (d, 1H), 8.33 (t, 2H), 9.03 (d, 1H), 9.09 (d, 1H).

Synthesis Example 21 Synthesis of Complex (XXI) a) Synthesis ofN1,N2-bis(4-tert-butylphenyl)benzene-1,2-diamine

12.0 g (81.6 mmol) of 1,2-dichlorobenzene and 26.8 g (0.18 mol) of4-tert-butylaniline are dissolved under argon in 100 ml of dioxane. 27.5g (0.25 mol) of potassium tert-butoxide are added first, followed by theaddition of 150 mg (0.41 mmol) allylpalladium(II) chloride dimer and 350mg (0.82 mmol) of 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride.The reaction mixture is three times evacuated and backfilled with argon,followed by heating at 94° C. during three hours. The reaction mixtureis diluted with 200 ml of toluene and filtered through a 5 cm layer ofHyflo® filter aid. The filtrate is concentrated under vacuum and theresidue dissolved in hot ethanol. The solution is cooled down to roomtemperature, and the resulting suspension filtered. The solid is washedwith ethanol and heptane, followed by drying under vacuum, giving thetitle product as a white solid (yield: 23.6 g (78%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.25 (s, 18H), 6.83-6.88 (m, 2H), 6.90 (d,4H), 7.09 (s, 2H), 7.16-7.25 (m, 6H).

b) Synthesis of 1,3-bis(4-tert-butylphenyl)benzimidazol-3-iumtetrafluoroborate

A dark blue suspension of 20.0 g (53.7 mmol) ofN1,N2-bis(4-tert-butylphenyl)benzene-1,2-diamine and 5.63 g (53.7 mmol)of ammonium tetrafluoroborate in 90 ml (0.54 mol) of triethylorthoformate are heated at 128° C. during three hours. The reactionmixture is cooled down to room temperature and diluted with 200 ml ofheptane. The dark suspension is filtered, the solid washed with heptane,followed by drying under vacuum, giving the title compound as anoff-white solid (yield: 24.9 g (99%).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.40 (s, 18H), 7.74-7.90 (m, 10H),7.91-8.01 (m, 2H), 10.45 (s, 1H).

c) Synthesis of Complex Intermediate (XXI-a)

6.00 g (12.8 mmol) of 1,3-bis(4-tert-butylphenyl)benzimidazol-3-iumtetrafluoroborate are suspended in 100 ml of toluene and cooled down to−12° C. 25.5 ml (12.8 mmol) of potassium bis(trimethylsilyl)amidesolution (KHMDS, 0.5M in toluene) are added within 20 minutes. Thecooling bath is removed and the suspension stirred during 30 minutesuntil room temperature is reached. The brown suspension is added within20 minutes to a preheated brownish solution of 4.28 g (6.37 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer in 70 ml toluene at 74° C.,and stirring continued at the same temperature during 30 minutes. Thehot reaction mixture is filtered through a 4 cm layer of silica gel andthe silica gel layer rinsed with toluene. The combined eluents areconcentrated under vacuum and the residue stirred in hot ethanol. Thesuspension is filtered, the solid washed with ethanol, followed bydrying under vacuum, giving the title product as a yellow solid (yield:7.78 g (85%)).

¹H-NMR (400 MHz, CDCl₃): δ=1.17-1.61 (m, 6H), 1.45 (s, 18H), 1.62-1.75(m, 2H), 2.40-2.50 (m, 2H), 4.44-4.55 (m, 2H), 7.23-7.38 (m, 2H),7.34-7.41 (m, 2H), 7.61 (d, 4H), 7.97 (d, 4H).

d) Synthesis of Complex (XXI)

4.62 g (12.5 mmol) of complex intermediate (XXI-a) and 4.50 g (6.26mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aresuspended in 100 ml of 1,2-dichlorobenzene, and heated at 123° C. duringduring 49 hours. The reaction mixture is cooled down to room temperatureand concentrated under vacuum to a volume of ca. 40 ml, followed by theaddition of 300 ml of ethanol and 300 ml of heptane. The resultingsuspension is filtered, the solid washed with 100 ml of ethanol,followed by drying under vacuum. The solid is further purified bychromatography (silica gel, dichloromethane/heptane). The isolatedproduct fractions are diluted with 100 ml of ethanol and concentratedunder vacuum until a suspension is formed. The suspension is filtered,the solid washed with ethanol, followed by drying under vacuum, givingthe title product as a yellow solid (yield: 2.71 g (36%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₉H₅₅IrN₁₀=1216.42; found1217.4 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.69 (s, 9H), 1.06 (s, 9H), 5.98-8.08 (br.signals, 8H), 6.28 (dd, 1H), 6.33 (dd, 1H), 6.40 (dd, 1H), 6.52 (d, 1H),6.59-6.65 (m, 2H), 6.70-6.77 (m, 2H), 6.82-6.94 (m, 3H), 7.12 (t, 1H),7.17-7.29 (m, 3H), 7.35-7.45 (m, 2H), 7.66-7.87 (m, 5H), 7.88-7.93 (m,1H), 7.95 (d, 1H), 8.22 (d, 1H), 8.30-8.38 (m, 2H), 9.09 (d, 2H).

Synthesis Example 22 Synthesis of Complex (XXII)

1.50 g (2.47 mmol) of complex intermediate (XX-a) and 2.37 g (4.93 mmol)of the 1,3-bis(4-tert-butylphenyl)-2-ethoxy-2H-imidazo[4,5-b]quinoxalineare dissolved in 70 ml of o-xylene, and heated at 141° C. during 21hours. The reaction mixture is cooled down to room temperature andconcentrated under vacuum. The residue is dissolved in dichloromethaneand filtered through a 4 cm layer of silica gel followed by rinsing thesilica gel layer with dichloromethane. The combined eluents areconcentrated under vacuum and the solid further purified bychromatography (silica gel, heptane/ethyl acetate 4:1). The isolatedproduct is dissolved in dichloromethane first, followed by the additionof 30 ml ethanol. The solution is concentrated until a suspension isformed. The suspension is filtered, the solid washed with ethanol andfurther dried under vacuum, giving the title product as a yellow solid(yield: 421 mg (13%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₇H₇₁IrN₁₀=1328.55; found1329.7 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=0.76 (s, 9H), 1.04 (s, 9H), 1.08 (s, 9H),1.09 (s, 9H), 6.05-7.97 (br. signals, 8H), 6.10 (d, 1H), 6.20 (t, 1H),6.38 (d, 1H), 6.48 (d, 1H), 6.56-6.66 (m, 2H), 6.68 (d, 1H), 6.73 (d,1H), 6.82 (t, 1H), 7.10 (t, 1H), 7.16-7.29 (m, 3H), 7.29-7.43 (m, 2H),7.68-7.76 (m, 2H), 7.77-7.85 (m, 2H), 7.88 (d, 2H), 8.09 (d, 1H),8.25-8.38 (m, 3H), 8.85 (d, 1H), 9.00 (d, 1H).

Synthesis Example 23 Synthesis of Complex (XXIII) a) Synthesis ofN1,N2-bis(3-ethylphenyl)benzene-1,2-diamine

11.1 g (75.8 mmol) of 1,2-dichlorobenzene and 20.2 g (0.17 mol) of3-ethylaniline are dissolved under argon in 100 ml of dioxane. 25.5 g(0.23 mol) of potassium tert-butoxide are added first, followed by theaddition of 139 mg (0.38 mmol) allylpalladium(II) chloride dimer and0.32 g (0.75 mmol) of 1,3-bis-(2,6-diisopropylphenyl)imidazoliumchloride. The reaction mixture is three times evacuated and backfilledwith argon, followed by heating at 92° C. during 90 minutes. The darksuspension is diluted with toluene and filtered through a 5 cm layer ofsilica gel, followed by rinsing the silica gel layer with 100 ml oftoluene. The collected eluents are concentrated under vacuum, and thendissolved in 100 ml of heptane and 200 ml of 20% aqueous hydrochloricacid, followed by stirring at 50° C. during 30 minutes. The suspensionis cooled down to room temperature, then filtered, and the solid washedwith water and heptane. The solid is suspended in 10% aqueous sodiumhydroxide and 100 ml of toluene. The toluene phase is separated thenwashed two times with 50 ml water, followed by drying over sodiumsulfate, and concentrated under vacuum, giving the title product as alight yellow oil (yield: 13.1 g (55%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.12 (t, 6H), 2.49 (q, 4H), 6.61 (d, 2H),6.74-6.81 (2 br. signals, 4H), 6.87-6.94 (m, 2H), 7.08 (t, 2H), 7.17 (s,2H), 7.20-7.27 (m, 2H).

b) Synthesis of 1,3-bis(3-ethylphenyl)benzimidazol-3-iumtetrafluoroborate

A dark blue suspension of 13.0 g (41.1 mmol) ofN1,N2-bis(3-ethylphenyl)benzene-1,2-diamine and 4.31 g (41.1 mmol) ofammonium tetrafluoroborate in 70 ml (0.42 mol) of triethyl orthoformateare heated under reflux during four hours. The reaction mixture iscooled down to room temperature and diluted with 200 ml of heptane,followed by stirring during 17 hours. The dark suspension is filtered,the solid washed with heptane and further dried under vacuum, giving thetitle compound as a light yellow solid (yield: 16.3 g (96%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.30 (t, 6H), 2.82 (q, 4H), 7.59-7.65 (2br. signals, 2H), 7.69-7.84 (m, 8H), 7.94-8.00 (m, 2H), 10.53 (s, 1H).

c) Synthesis of Complex Intermediate (XXIII-a)

5.00 g (12.1 mmol) of 1,3-bis(3-ethylphenyl)benzimidazol-3-iumtetrafluoroborate are suspended in 100 ml of toluene and cooled down to−13° C. 24.0 ml (12.0 mmol) of potassium bis(trimethylsilyl)amidesolution (KHMDS, 0.5M in toluene) are added within 15 minutes. Thecooling bath is removed and the suspension stirred during 30 minutesreaching room temperature. The brown suspension is added within 35minutes to a preheated brownish solution of 4.05 g (6.03 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer in 70 ml toluene at 74° C.,and stirring continued at the same temperature during three hours. Thewarm reaction mixture is filtered through a 3 cm layer of silica gel,and the silica gel layer rinsed with toluene. The collected eluents areconcentrated under vacuum and stirred in warm ethanol. The suspension isfiltered, the solid washed with ethanol and further dried under vacuum,giving the title product as a yellow solid (yield: 5.5 g (69%)).

¹H-NMR (400 MHz, CDCl₃): δ=1.18-1.29 (m, 2H), 1.33-1.51 (2 m, 4H), 1.38(t, 6H), 1.65-1.79 (m, 2H), 2.45-2.52 (m, 2H), 2.75-2.90 (m, 4H),4.46-4.54 (m, 2H), 7.24-7.30 (m, 2H), 7.33-7.41 (m, 4H), 7.50 (t, 2H),7.76 (d, 2H), 8.06 (s, 2H).

d) Synthesis of Complex (XXIII)

3.00 g (4.53 mmol) of complex intermediate (XXIII-a) and 3.34 g (9.07mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aredissolved in 90 ml of 1,2-dichlorobenzene, and heated first at 112° C.during 20 hours, followed by heating at 123° C. during 48 hours. Thereaction mixture is cooled down to room temperature, diluted with 200 mlof acetone, and stirred during three hours. The suspension is filtered,the solid washed with acetone and ethanol and further dried undervacuum, giving the title product as a yellow solid (yield: 1.69 g(32%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₅H₄₇IrN₁₀=1160.36; found1161.4 [M+1]⁺.

Synthesis Example 24 Synthesis of Complex (XXIV) a) Synthesis ofN1,N2-bis(4-phenylphenyl)benzene-1,2-diamine

10.9 g (73.9 mmol) of 1,2-dichlorobenzene and 25.0 g (0.15 mol) of4-biphenylamine are dissolved under argon in 100 ml of dioxane. 24.9 g(0.22 mol) of potassium tert-butoxide are added first, followed by theaddition of 135 mg (0.37 mmol) allylpalladium(II) chloride dimer and 315mg (0.74 mmol) of 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride.The reaction mixture is three times evacuated and backfilled with argon,followed by heating under reflux during 20 hours. 5.00 g (29.5 mmol) of4-biphenylamine are added and heating continued during 24 hours. Thereaction mixture is cooled down to room temperature, then diluted with200 ml of toluene, followed by filtration through Hyflo® filter aid. Thefilter aid is rinsed with toluene and the combined eluents concentratedunder vacuum. The residue is stirred in ethanol under reflux and theresulting suspension filtered. The solid is washed with ethanol anddissolved in 600 ml of dichloromethane. 100 ml of a 5% aqueous sodiumcyanide solution are added under stirring and stirring continued during30 minutes. The organic phase is separated and two times washed with 100ml of water, and further diluted with 200 ml of ethanol. The solution isconcentrated under vacuum until a suspension is formed. The suspensionis filtered, the solid washed with ethanol, followed by drying undervacuum, giving the title product as a solid (yield: 15.3 g (50%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=6.91-7.02 (m, 2H), 7.06 (d, 4H), 7.22-7.36(m, 4H), 7.41 (t, 4H), 7.50 (s, 2H), 7.48-7.55 (m, 4H), 7.56-7.63 (m,4H).

b) Synthesis of 1,3-bis(4-phenylphenyl)benzimidazol-3-iumtetrafluoroborate

A beige suspension of 10.0 g (24.2 mmol) ofN1,N2-bis(4-phenylphenyl)benzene-1,2-diamine, 2.54 g (24.2 mmol) ofammonium tetrafluoroborate and 36.6 g (0.25 mol) of triethylorthoformate is heated at 112° C. during 15 minutes. An additional 36.6g (0.25 mol) of triethyl orthoformate are added and heating continued at119° C. during 4 h 30 min. The beige suspension is cooled down to roomtemperature first, then diluted with ethanol, and filtered. Theresulting solid is washed with ethanol first, followed by drying undervacuum, giving the title product as an off-white solid (yield: 11.6 g(94%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.49 (t, 2H), 7.58 (t, 4H), 7.82-7.89 (m,6H), 8.03-8.09 (m, 6H), 8.10-8.16 (m, 4H), 10.65 (s, 1H).

c) Synthesis of Complex Intermediate (XXIV-a)

4.56 g (8.94 mmol) of 1,3-bis(4-phenylphenyl)benzimidazol-3-iumtetrafluoroborate are suspended in 50 ml of toluene and cooled down to−14° C. 18.0 ml (9.00 mmol) of potassium bis(trimethylsilyl)amidesolution (KHMDS, 0.5M in toluene) are added within 15 minutes. Thecooling bath is removed and the suspension stirred during 25 minutesuntil room temperature is reached. 3.00 g (4.47 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer are added and the suspensionheated at 63° C. during 1 h 40 min. The hot reaction mixture is filteredthrough Hyflo® filter aid, followed by rinsing the filter aid withtoluene. The combined eluents are partly concentrated under vacuum anddiluted with 100 ml of ethanol. The resulting suspension is filtered,the solid dried under vacuum, giving the title product as a yellow solid(yield: 4.10 g (61%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.18-1.30 (m, 2H), 1.32-1.46 (m, 4H),1.61-1.74 (m, 2H), 2.57-2.66 (m, 2H), 4.30-4.39 (m, 2H), 7.38-7.51 (m,6H), 7.56 (t, 4H), 7.85 (d, 4H), 7.98 (d, 4H), 8.18 (d, 4H).

d) Synthesis of Complex (XXIV)

4.00 g (5.27 mmol) of complex intermediate (XXIV-a) and 7.80 g (21.1mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aredissolved under argon in 100 ml of chlorobenzene. The green-brownsolution is three times evacuated and backfilled with argon, followed byheating at 124° C. during 19 hours. The orange-brown solution is cooleddown to room temperature first, then treated with 400 ml of acetone, andstirring continued during one hour. The resulting suspension isfiltered, the solid washed with 100 ml of acetone and 200 ml of ethanol.The solid is dissolved in 75 ml of dichloromethane and filtered througha 4 cm layer of silica gel, followed by rinsing the silica gel layerwith 400 ml of dichloromethane. The combined eluents are treated with100 ml of acetone, and concentrated under vacuum to a volume of 50 mluntil a suspension is formed. The suspension is filtered, the solidwashed with 100 ml of acetone and 50 ml of pentane, followed by dryingunder vacuum. The solid is further purified by chromatography (silicagel, dichloromethane/heptane), giving the title product as a yellowsolid (yield: 4.23 g (44%)).

APCI-LC-MS (positive, m/z): exact mass of C₇₃H₄₇IrN₁₀=1256.36; found1257.4 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=5.98-7.70 (br. signal, 8H), 6.46 (dd, 1H),6.57-6.64 (m, 2H), 6.64-6.72 (m, 4H), 6.73-6.83 (m, 2H), 6.85-6.95 (m,3H), 6.95-7.03 (m, 3H), 7.11 (t, 1H), 7.14-7.23 (m, 2H), 7.24-7.33 (m,4H), 7.33-7.39 (m, 2H), 7.43 (t, 1H), 7.50 (dd, 1H), 7.56-7.65 (m, 3H),7.71-7.79 (m, 2H), 7.80-7.86 (m, 1H), 7.91 (dd, 1H), 8.12 (d, 1H), 8.27(t, 2H), 8.33 (dd, 1H), 9.09 (dd, 1H), 9.13 (dd, 1H).

Synthesis Example 25 Synthesis of Complex (XXV) a) Synthesis of5,6-dicyano-1,3-diphenyl-benzimidazolium tetrafluoroborate

22.6 g (170 mmol) of chloromethylene-dimethyliminium chloride (Vilsmeyerreagent) are dissolved in 270 ml of acetonitrile at −5° C. 9.20 g (26.6mmol) 4,5-dianilinophthalic acid diamide described in EP0600832 areadded in portions within 5 minutes. The dark green solution is stirredfor one hour at 0° C. The reaction mixture is warmed up to roomtemperature and stirred overnight. 19.0 g (173 mmol) of sodiumtetrafluoroborate are added to the dark blue solution. After stirringthe suspension for 4.5 hours the solid is filtered off and washed withacetonitrile. The filtrate is concentrated. 100 ml of an ice-watermixture are added. After stirring the suspension for 30 min the residueis filtered off, washed three times with 20 ml ice-cold water each, andis sucked dry. The solid is suspended three times in 20 ml ofisopropanol each, sucked dry, and is washed twice with 20 ml ofn-pentane each. The solid is dried under vacuum in a drying cabinet at60° C. for 16 hours. 10.6 g (94% of theory) slightly turquoise solid areobtained.

¹H-NMR (400 MHz, CD₃CN): δ [ppm]=7.80 (mc; 10H), 8.50 (mc; 2H), 9.78 (s;1H).

b) Synthesis of2-methoxy-1,3-diphenyl-2H-benzimidazol-5,6-dicarbonitrile

10.6 g (26.0 mmol) of 5,6-dicyano-1,3-diphenyl-benzimidazoliumtetrafluoroborate are suspended in 250 ml of methanol. After cooling thesuspension to 0° C. a solution, 4.68 g (26.0 mmol) of sodium methoxidein methanol (30%) is added within 10 minutes. The reaction mixture isstirred at 0° C. for 40 minutes and then warmed up to room temperatureand stirred for three hours. The residue is filtered off, washed threetimes with 10 ml of ice-cold methanol, and dried under vacuum in dryingcabinet overnight at 50° C. 8.51 g (93% of theory) greenish solid areobtained.

¹H-NMR (400 MHz, CD₂Cl₂): δ [ppm]=3.17 (s; 3H), 7.02 (s; 1H), 7.19 (mc;2H), 7.32 (mc; 2H), 7.50 (mc; 8H).

c) Synthesis of Complex Intermediate (XXV-a)

9.50 g (27.0 mmol)2-methoxy-1,3-diphenyl-2H-benzimidazol-5,6-dicarbonitrile and 9.05 g(13.5 mmol) of μ-chloro-1,5-cyclooctadiene-iridium(I) dimer are added to500 ml toluene. The flask is rinsed with 150 ml of toluene. Afterheating the suspension to 60° C. a solution is formed which is heated atthat temperature for 24 hours. The suspension is cooled to 15° C. andthen filtered. The residue is washed five times with 5 ml of toluene,then three times with 10 ml of n-pentane, and dried under vacuum indrying cabinet at 60° C. during 16 hours. 14.1 g (80% of theory) of anolive-green solid are obtained.

¹H-NMR (400 MHz, CD₂Cl₂): δ [ppm]=1.30-1.60 (m; 6H), 1.71 (mc; 2H), 2.54(mc; 2H), 4.57 (mc; 2H), 7.68 (mc; 6H), 7.73 (mc; 2H), 7.99 (mc; 4H).

d) Synthesis of Complex (XXV)

1.00 g (1.52 mmol) of complex intermediate (XXV-a) and 2.25 g (6.10mmol) 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are suspendedin 30 ml of chlorobenzene. The suspension is heated to 125° C. andstirred at that temperature for 17 hours. After cooling the reactionmixture to room temperature 15 ml of acetone and 45 ml of absoluteethanol are added. The suspension is stirred for 30 minutes and thenfiltered. The filtrate is evaporated to dryness. The brown solid isdissolved in 5 ml of dichloromethane and then precipitated by adding 7ml of absolute ethanol. The precipitate is filtered off, three timeswashed with 3 ml of n-pentane, and dried under vacuum in drying cabinetat 60° C. overnight. A dark yellow solid is obtained that is furtherpurified by MPLC with the CombiFlash Companion (silica gel,dichloromethane/methanol 99.5:0.5). The purified yellow solid (0.52 g)is boiled up in 10 ml of acetonitrile. The hot suspension is filtered.The residue is washed three times with 1 ml of acetonitrile, then washedtwice with 3 ml of ethanol, and three times with 3 ml of n-pentane, anddried under vacuum in a drying cabinet at 100° C. overnight. The yellowsolid (0.41 g) obtained is again purified by boiling up in acetonitrileas described before. The yellow solid is purified by MPLC a second timeas described before. The yellow solid is boiled up in acetonitrile againas described before. 225 mg (13% of theory) yellow solid are obtained.

ESI-LC/MS (positive, m/z): exact mass of C₆₃H₃₇IrN₁₂=1154.29; found1154.2 [M+H]⁺

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=6.30 (mc), 6.39 (mc), 6.53-6.61 (m),6.68 (mc), 6.78-6.84 (m), 6.88 (mc), 6.92 (mc), 7.21 (mc), 7.36 (mc),7.72 (mc; 2H), 7.78-7.87 (m; 5H), 8.29 (mc; 2H), 8.56 (mc; 1H), 9.01(mc; 2H).

Synthesis Example 26 Synthesis of Complex (XXVI)

A suspension of 8.69 g (24.3 mmol) of 1,3-diphenylbenzimidazol-3-iumtetrafluoroborate (see synthesis in WO2005/019373) in 50 ml of tolueneis cooled down to −11° C. 48.6 ml (24.3 mmol) of potassiumbis(trimethylsilyl)amide solution (KHMDS, 0.5M in toluene) are addedwithin 20 minutes. The cooling bath is removed and stirring continueduntil room temperature is reached. The green suspension is treated with4.00 g (6.07 mmol) of complex intermediate (VIII-a) and 100 ml oftoluene, and heated at 109° C. during three hours. The reaction mixtureis cooled down to room temperature, filtered, and the solid washed with50 ml of toluene. The combined filtrates are diluted with 300 ml ofethanol and 500 ml of heptane, followed by stirring during one hour. Thesuspension is filtered, the solid washed with ethanol and heptane,followed by drying under vacuum. The solid is further purified bychromatography (silica gel, dichloromethane/heptane), giving the titleproduct as a yellow solid (yield: 1.64 g (26%)).

APCI-LC-MS (positive, m/z): exact mass of C₅₉H₃₉IrN₈=1052.29; found1053.3 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.23-7.49 (br. signal, 4H), 6.25-6.40 (m,4H), 6.45 (d, 1H), 6.49-6.61 (m, 3H), 6.61-6.69 (m, 3H), 6.70-6.89 (m,6H), 7.06-7.24 (m, 5H), 7.27-7.41 (m, 4H), 7.68-7.75 (m, 1H), 7.77-7.84(m, 1H), 7.88 (d, 1H), 7.98-8.08 (m, 2H), 8.20 (t, 2H), 8.31 (d, 1H),9.02 (d, 1H).

Synthesis Example 27 Synthesis of Complex (XXVII) a) Synthesis ofN2,N3-diphenylnaphthalene-2,3-diamine

A mixture of 25 g (0.16 mol) of 2,3-diaminonaphthalene, 49.6 g (0.32mol) of bromobenzene and 250 ml of toluene is degassed under vacuum andbackfilling with argon (repeated three times). 1.45 g (1.58 mmol) ofdipalladium tris(dibenzylidene acetonate), 2.74 g (4.74 mmol) ofXantPhos ligand (=4,5-bis(diphenylphosphino)-9,9-dimethylxanthene), 21.0g sodium tert-butoxide (0.22 mol) and 2.84 ml of degassed water areadded and the mixture degassed again 3 times with vacuum/argonbackfilling. The dark suspension is refluxed under argon for 20 hoursand cooled to room temperature. The mixture is diluted with 400 ml ofdichloromethane, extracted twice with a 1% aqueous solution of sodiumcyanide, washed three times with water, dried over sodium sulfate, andconcentrated under vacuum. The residue is purified by chromatography(silica gel, dichloromethane 99.5%:triethylamine 0.5%) to give the titleproduct as a brown powder (yield: 23.5 g (48%)).

¹H-NMR (300 MHz, CDCl₃): δ=7.67 (s, 2H), 7.64-7.60 (m, 2H), 7.37-7.27(m, 6H), 7.10 (m, 4H), 7.00 (tt, 2H), 5.84 (s, 2H).

b) Synthesis of 1,3-diphenylbenzo[f]benzimidazol-3-ium tetrafluoroborate

A mixture of 22 g of N2,N3-diphenylnaphthalene-2,3-diamine (71 mmol) and7.44 g ammonium tetrafluoroborate (71 mmol) in 154.8 g triethylorthoformate (1.05 mol) is heated for 20 hours at 100° C. in a reactorfitted with a Dean-Stark separator and condenser. The reaction mixtureis cooled to 15° C. and the precipitate is rinsed with cold triethylorthoformate and heptane. The crude product is dissolved in 600 ml ofdichloromethane, filtered, and the filtrate concentrated under vacuum.The title product is obtained as a brown powder (yield: 24 g (85%)).

¹H-NMR (300 MHz, d₆-DMSO): δ=10.74 (s, 1H), 8.61 (s, 2H), 8.30 (m, 2H),8.05 (m, 4H), 7.85 (m, 6H), 7.71 (m, 2H).

c) Synthesis of N2,N3-bis(4-isopropylphenyl)quinoxaline-2,3-diamine(XXVII-a)

5.00 g (12.2 mmol) of 1,3-diphenylbenzo[f]benzimidazol-3-iumtetrafluoroborate are suspended in 100 ml of toluene and cooled down to−13° C. 24.5 ml (12.3 mmol) of potassium bis(trimethylsilyl)amidesolution (KHMDS, 0.5M in toluene) are added within 20 minutes. Thecooling bath is removed and the suspension stirred during one hour untilroom temperature is reached. The orange suspension is treated with 4.11g (6.12 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer and 50 ml oftoluene, and then heated at 66° C. during one hour. The hot reactionmixture is filtered through a 3 cm layer of Hyflo® filter aid, and thefilter aid layer rinsed with 30 ml of toluene. The combined eluents areconcentrated under vacuum, and the black residue stirred in 100 ml ofethanol during 15 minutes. The resulting suspension is filtered, thesolid washed with 30 ml of ethanol, followed by drying under vacuum,giving the title product as a greenish yellow solid (yield: 4.54 g(56%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=1.19-1.49 (m, 6H), 1.57-1.71 (m, 2H),2.58-2.66 (m, 2H), 4.28-4.37 (m, 2H), 7.47-7.54 (m, 2H), 7.63-7.76 (m,2H), 7.88 (s, 2H), 8.05-8.11 (m, 2H), 8.11-8.17 (m, 4H).

d) Synthesis of Complex (XXVII)

4.00 g (6.10 mmol) of complex intermediate (XXVII-a) and 9.00 g (24.4mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aredissolved under argon in 100 ml of chlorobenzene. The dark solution isthree times evacuated and backfilled with argon, followed by heating at126° C. during 23 hours. The reaction mixture is treated with 100 ml ofDMF and then cooled down to room temperature, followed by stirring atice-bath temperature during 30 minutes. The suspension is filtered andthe resulting solid washed with 20 ml of DMF. The solid is furtherstirred in 20 ml of DMF, and the resulting suspension filtered, followedby stirring the solid two times in 30 ml of ethanol first, and then twotimes in 30 ml of heptane. The suspension is filtered and the soliddried under vacuum. The solid is dissolved in 80 ml of hot NMP. Thebrownish yellow solution is cooled down to room temperature and theresulting suspension stirred during 30 minutes. The suspension isfiltered, the solid washed with 20 ml of NMP first, then 50 ml ofethanol and 50 ml of heptane, followed by drying under vacuum. Theyellow solid is stirred in 1 L of dichloromethane during one hour,followed by filtration. The filtrate is treated with 10 g of Hyflo®filter aid, and concentrated under vacuum. The solid Hyflo®-productmixture is subjected to further purification by chromatography (silicagel, dichloromethane/toluene), giving the title product as a yellowsolid (yield: 1.73 g (25%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₅H₄₁IrN₁₀=1154.31; found1155.4 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.04-7.63 (br. signal, 8H), 6.44 (m, 2H),6.54-6.78 (m, 7H), 6.79-6.91 (m, 4H), 7.17-7.34 (m, 3H), 7.39 (t, 1H),7.48 (t, 1H), 7.57 (t, 1H), 7.67-7.80 (m, 3H), 7.80-7.96 (m, 4H), 8.17(d, 1H), 8.24 (d, 1H), 8.35 (t, 2H), 8.64 (s, 1H), 9.03 (d, 1H), 9.10(d, 1H).

Synthesis Example 28 Synthesis of Complex (XXVIII)

A suspension of 9.40 g (23.0 mmol) of1,3-diphenylbenzo[f]benzimidazol-3-ium tetrafluoroborate in 150 ml oftoluene is cooled down to −12° C. 46.1 ml (23.1 mmol) of potassiumbis(trimethyl-silyl)amide solution (KHMDS, 0.5M in toluene) are addedwithin 25 minutes at a maximum temperature of −9° C. The cooling bath isremoved and stirring continued until room temperature is reached. Thered suspension is treated with 3.80 g (5.76 mmol) of complexintermediate (VIII-a), and heated under reflux during 75 minutes. Thehot orange-brown suspension is filtered through a 3 cm layer of Hyflo®filter aid, and the filter aid rinsed with 30 ml of toluene. Thecombined eluents are diluted with 600 ml of ethanol and stirred during45 minutes. The suspension is filtered, the solid washed with ethanol,followed by drying under vacuum. The solid is further purified bychromatography (silica gel, dichloromethane/heptane), giving the titleproduct as a yellow solid (yield: 3.49 g (53%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₇H₄₃IrN₈=1152.32; found1153.3 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.26-7.63 (br. signal, 4H), 6.27-6.50 (m,4H), 6.57 (t, 1H), 6.61-6.88 (m, 12H), 6.90 (s, 1H), 7.15-7.32 (m, 3H),7.34-7.60 (m, 5H), 7.65-7.94 (m, 5H), 8.10-8.28 (m, 4H), 8.32 (dd, 1H),8.61 (d, 2H), 9.03 (dd, 1H).

Synthesis Example 29 Synthesis of Complex (XXIX) a) Synthesis of1,3-diphenylimidazol-1-ium tetrafluoroborate

A solution of 50.0 g (0.34 mol) of a 40% aqueous glyoxal solution, 65.3g (0.70 mol) of aniline and 500 ml of ethyl acetate is stirred over anice-bath during one hour. The ice-bath is removed and the reactionmixture stirred at room temperature during one hour. The light orangesolution is slowly treated at ice-bath temperature with an ice-coldsuspension of 5.20 g of paraformaldehyde in 120 ml of 1,4-dioxane and 52g of concentrated aqueous hydrochloric acid, followed by stirring during20 minutes. The ice-bath is removed and stirring continued until roomtemperature is reached, followed by stirring during one hour at roomtemperature. The resulting suspension is treated with 500 ml ofsaturated aqueous sodium hydrogencarbonate solution first, thenfiltered, and the solid washed with ethyl acetate. The water phase isseparated of the filtrate solution, and two times washed with 100 ml ofethyl acetate. The water phase is further treated with 45.4 g of 48%aqueous solution of tetrafluoroboric acid and stirred for a short time.The resulting suspension is filtered and the solid dried under vacuum,giving the title product as a white solid (yield: 22.7 g (21%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.65 (t, 2H), 7.73 (t, 4H), 7.93 (d, 4H),8.58 (d, 2H), 10.34 (s, 1H).

b) Synthesis of Complex Intermediate (XXIX-a)

0.92 g (14.0 mmol) of 1,3-diphenylimidazol-1-ium tetrafluoroborate aresuspended under argon in 15 ml of toluene and cooled down to −10° C. 6.0ml (3.0 mmol) of potassium bis(trimethylsilyl)-amide solution (KHMDS,0.5M in toluene) are dropwise added at a max. temperature of −8° C. Thecooling bath is removed and the suspension stirred until roomtemperature is reached. The orange suspension is dropwise added to apreheated brownish solution of 1.00 g (1.49 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer in 15 ml of toluene at 74°C., and stirring continued at the same temperature during two hours. Thewarm orange suspension is diluted with 50 ml of toluene and filteredthrough a 3 cm layer of silica gel and the silica gel layer rinsed withtoluene. The collected fractions are concentrated under vacuum and theresulting solid dissolved in a minimal amount of dichloromethane,followed by the addition of 30 ml of ethanol. The solution isconcentrated until a suspension is generated. The suspension isfiltered, the solid washed with cold ethanol and dried under vacuum,giving the title compound as a yellow solid (yield: 0.64 g (39%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.17-1.31 (m, 2H), 1.40-154 (m, 4H),1.74-1.89 (m, 2H), 2.37-2.45 (m, 2H), 4.40-4.48 (m, 2H), 7.39 (s, 2H),7.47-7.61 (m, 6H), 8.11-8.18 (m, 4H).

c) Synthesis of Complex (XXIX)

0.50 g (0.90 mmol) of complex intermediate (XXIX-a) and 1.34 g (3.64mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aredissolved under argon in 25 ml of chlorobenzene. The yellow solution isthree times evacuated and backfilled with argon, followed by heating at116° C. during 16 hours. The reaction mixture is cooled down to roomtemperature and treated with 20 ml of ethanol, followed by stirringduring 30 minutes. The suspension is filtered, the solid washed withethanol first, followed by washing with heptane. The collected filtratesare concentrated under vacuum, and further purified by chromatography(silica gel, dichloromethane/heptane). The pure product fractions arecollected and concentrated under vacuum, until a suspension is formed.The suspension is filtered, the solid washed with ethanol, followed bydrying under vacuum, giving the title product as a yellow solid (yield:0.3 g (32%)).

APCI-LC-MS (positive, m/z): exact mass of C₅₇H₃₇IrN₁₀=1054.28; found1055.2 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.21-7.66 (br. signals, 8H), 6.35 (dd, 2H),6.48 (tt, 1H), 6.55 (d, 1H), 6.56-6.65 (m, 3H), 6.66-6.90 (m, 7H), 7.10(td, 1H), 7.24 (td, 2H), 7.40 (m, 1H), 7.49 (d, 1H), 7.68-7.88 (m, 5H),7.93 (dd, 1H), 8.29 (dd, 1H), 8.34 (dd, 1H), 8.97 (dd, 1H), 9.08 (dd,1H).

Synthesis Example 30 Synthesis of Complex (XXX) a) Synthesis of ComplexIntermediate (XXX-a)

0.50 g (1.64 mmol) of 1,3-Diphenyl-imidazo[4,5-b]pyridiniumchloride(synthesis described in WO2011/073149, example 26) are dissolved in 10ml toluene and cooled to −10° C. 3.28 ml (1.64 mmol) of a 0.5M KHMDSsolution in toluene are added to the solution within five minutes. Thesolution is stirred another five minutes and then slowly warmed up toroom temperature. 0.55 g (0.82 mmol)μ-chloro-1,5-cyclooctadien-iridium(I) dimer are added to the reactionmixture. After heating the suspension to 60° C. it is held at thattemperature for 20.5 hours. The suspension is cooled to room temperatureand then filtered through Decalite Speed. The filtrate is washed withwater and then with brine. The organic solution is dried with magnesiumsulfate and filtered. The solution is concentrated under vacuum. Thesolid (0.83 g) is dissolved in dichloromethane and adsorbed on 2 g ofDecalite Speed. The solid is filtered off and further purified by MPLCwith the CombiFlash Companion (silica gel, ethyl acetate/n-heptane),giving the title product as a yellow solid (yield: 0.21 g (21%)).

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=1.29-1.34 (m, 2H), 1.29-1.52 (m, 4H),1.74 (mc, 2H), 2.50-2.59 (m, 2H), 4.48 (mc, 2H), 7.25 (mc, 1H),7.54-7.66 (m, 7H), 8.05 (mc, 2H), 8.12 (mc, 2H), 8.32 (mc, 1H).

b) Synthesis of Complex (XXX)

0.40 g (0.66 mmol) of complex intermediate (XXX-a) and 0.49 g (1.32mmol) 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are dissolvedin 20 ml o-xylene. The solution is heated to 115° C. and held at thattemperature for 21.5 hours. After cooling the reaction mixture to roomtemperature it is evaporated to dryness. The solid is added to ethylacetate. After the suspension has been filtered the filtrate isevaporated to dryness. The solid is purified by MPLC with the CombiFlashCompanion (silica gel, ethyl acetate/n-heptane). After evaporating thesolvent the solid is recrystallized in toluene. The solid is filtered,and dried under vacuum, giving the title product as a yellow solid(yield: 20 mg (3%)).

ESI-LC/MS (positive, m/z): exact mass of C₆₀H₃₈IrN₁₁=1105.29; found1106.3 [M+H]⁺.

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=6.28-7.36 (m; 26H), 7.72 (mc; 2H),7.76-7.88 (m; 4H), 8.30 (mc; 2H), 8.41 (mc; 1H), 9.02 (mc, 3H).

Synthesis Example 31 Synthesis of Complex (XXXI) a) Synthesis of2-ethoxy-1-(o-tolyl)-3-phenyl-6-(trifluoromethyl)-2H-imidazo[4,5-b]pyridine

5.32 g (14.0 mmol) HCl-Adduct of2,3-dianilino-5-trifluoromethyl-pyridine are heated in 45 g triethylorthoformate at 120° C. for 16 h. The reaction mixture is evaporated todryness in vacuum. 6.39 g oil are obtained containing small amounts oftriethyl orthoformate.

b) Synthesis of Complex Intermediate (XXXI-a)

A solution of 6.39 g of2-ethoxy-1-(o-tolyl)-3-phenyl-6-(trifluoromethyl)-2H-imidazo[4,5-b]pyridineand 4.49 g (6.68 mmol) μ-chloro-cyclooctadien-iridium dimer in 75 mltoluene is heated at 55° C. for 50 min. The reaction mixture isevaporated to dryness in vacuum. 50 ml ethanol are added to the residue.The mixture is stirred during five minutes and then filtered. The solidis dried under vacuum giving the title product as a solid (yield: 5.32g).

c) Synthesis of Complex (XXXI)

A solution of 12.83 g (34.8 mmol) complex intermediate (XXXI-a) and 8.00g 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline in 300 mlo-dichlorobenzene is heated at 150° C. for one hour. After cooling thereaction mixture to room temperature the suspension is filtered. Theresidue is purified by MPLC with CombiFlash Companion (silica gel,dichloromethane/n-heptane), giving the title product as a yellow solid(yield: 2.80 g (20%)).

MALDI-MS (positive, m/z): exact mass of C₆₂H₃₉F₃IrN₁₁=1187.30; found1187 [M+H]⁺

¹H-NMR (500 MHz, d₆-DMSO): δ [ppm]=0.77 (s; 3H), 6.20 (mc; 1H),6.50-6.65 (m; 5H), 6.68-6.78 (m; 4H), 6.82 (mc; 1H), 6.90-7.23 (m; 9H),7.78 (mc, 2H), 7.81-7.90 (m; 4H), 8.25 (mc; 1H), 8.31 (mc; 1H), 8.72(mc; 1H), 8.81 (mc; 1H), 8.84 (mc; 1H), 8.95 (mc; 1H).

Synthesis Example 32 Synthesis of Complex (XXXII) a) Synthesis ofphenanthrene-9,10-dione oxime

12.6 g (61 mmol) 9,10-Phenthrenedione, 16.9 g (243 mmol) hydroxylaminehydrochloride, 12.5 g (152 mmol) sodium acetate and 250 ml ethanol areheated under reflux over night. After cooling to room temperature theprecipitate is filtered off. The solid residue is suspended in water (50ml) and filtered off. It is washed with water and petroleum spirits. Thecrude product is recrystallized from methanol. Isomers ofphenanthrene-9,10-dione oxime are obtained as light-orange solid (yield:11.9 g (83%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.43-7.50 (m, 2H), 7.52-7.60 (m, 2H),7.80+7.85 (2×d, 1H), 8.09-8.15 (m, 2H), 8.46-8.49 (m, 1H),12.20+12.24+12.31+12.49 (4×s, 2H).

b) Synthesis of phenanthrene-9,10-diamine hydrochloride

3.4 g (14.3 mmol) of phenanthrene-9,10-dione oxime are dissolved inrefluxing ethanol (135 ml). The solution is cooled below 70° C. and 14.9g (78.5 mmol) SnCl₂ dissolved in 135 ml hydrochloric acid (32%) areadded dropwise within 10 minutes. The reaction mixture starts to refluxupon the exothermic reaction. The reaction is refluxed for additional 10minutes. After cooling to room temperature the precipitate is filteredoff and is washed with ethanol. The crude product is directly used inthe next reaction.

c) Synthesis of 1,4-dihydrophenanthro[9,10-b]pyrazine-2,3-dione

3.5 g (14.3 mmol) of crude phenanthrene-9,10-diamine hydrochloride and9.34 g (111 mmol) NaHCO₃ are suspended in 140 ml diethyl oxalate. Themixture is heated to 130° C. overnight. After cooling to roomtemperature the precipitate is filtered off. The residue is suspended in100 ml water and filtered off. The solid is washed with ethanol anddried under vacuum. 1,4-Dihydrophenanthro[9,10-b]pyrazine-2,3-dione isobtained as light-orange powder (yield: 481 mg (13% w.r.t.phenanthrene-9,10-dione oxime)).

¹H-NMR (500 MHz, d₆-DMSO): δ=7.71-7.77 (m, 4H), 8.69 (d, 2H), 8.91 (d,2H), 12.17 (s, br, 2H).

d) Synthesis of 2,3-dichlorophenanthro[9,10-b]pyrazine

600 mg (2.29 mmol) of 1,4-dihydrophenanthro[9,10-b]pyrazine-2,3-dioneare dissolved in 9 ml DMF under argon. 4 ml (6.28 g, 20 mmol) PCl₃ areadded dropwise and the reaction mixture is heated to 100° C. for 3.5 h.After cooling to room temperature the reaction mixture is quenched withwater. The precipitate is filtered off and washed with ethanol. Afterdrying under vacuum 2,3-dichlorophenanthro[9,10-b]pyrazine is obtainedas light-brown solid (yield: 539 mg (78%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.90 (t, 2H), 7.99 (t, 2H), 8.95-8.99 (m,4H).

e) Synthesis of N2,N3-diphenylphenanthro[9,10-b]pyrazine-2,3-diamine

582 mg (1.95 mmol) of 2,3-dichlorophenanthro[9,10-b]pyrazine and 0.43 ml(435 mg, 2.4 mmol) aniline are dissolved in 5 ml THF under argon. Thesolution is degassed. 106 mg (0.12 mmol) BrettPhos Pd(II) (G3) and 63 mg(0.12 mmol) BrettPhos ligand are added. 4.7 ml LiHMDS (4.7 mmol in THF)are added dropwise within 5 minutes. Then, the reaction mixture isheated under reflux over night. After cooling to room temperature thereaction is quenched with ice and 1 M hydrochloride acid. Solids arefiltered off and the filtrate is diluted with 20 ml dichloromethane. Thelayers are separated and the aqueous layer is extracted withdichloromethane (2×20 ml). The combined organic layers are washed withbrine (20 ml) and dried over Na₂SO₄. The solvent is removed in vacuo.The crude product is recrystallized from methanol.N2,N3-Diphenylphenanthro[9,10-b]pyrazine-2,3-diamine is obtained aslight-brown solid (yield: 435 mg (54%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=7.18 (t, 2H), 7.54 (t, 4H), 7.72-7.80 (m,4H), 8.04 (d, 4H), 8.83-8.86 (m, 4H), 9.20 (s, 2H).

f) Synthesis of(1,3-bisphenyl-2-ethoxy-2H-imidazo)phenanthro[9,10-b]pyrazine

225 mg (0.55 mmol) ofN2,N3-diphenylphenanthro[9,10-b]pyrazine-2,3-diamine, 2.5 ml (2.23 g, 15mmol) triethyl orthoformate and 5 mg (0.05 mmol) NH₄BF₄ are heated to135° C. with stirring for 10 h under argon. After cooling to roomtemperature the residue is suspended in ethanol and filtered off. Afterdrying in vacuo(1,3-bisphenyl-2-ethoxy-2H-imidazo)phenanthro[9,10-b]pyrazine isobtained as light-brown solid (yield: 131 mg (51%)).

¹H-NMR (400 MHz, d₆-DMSO): δ=0.96 (t, 3H), 3.35 (H₂O peak+q, 2H), 7.35(t, 2H), 7.68 (t, 4H), 7.78 (t, 2H), 7.84 (m, 2H), 8.09 (s, 1H), 8.39(d, 4H), 8.89 (d, 2H), 9.01 (d, 2H).

g) Synthesis of Intermediate Complex (XXXII-a)

115 mg (0.24 mmol) of(1,3-bisphenyl-2-ethoxy-2H-imidazo)phenanthro[9,10-b]pyrazine and 84 mg(0.12 mmol) of chloro(1,5-cyclooctadiene)iridium(I) dimer are dissolvedin 5 ml toluene. The suspension is degassed and subsequently heated to80° C. Upon heating a dark solution is obtained. Stirring at 80° C. iscontinued over night. After cooling a precipitate is formed and filteredoff and the solid is washed with ethanol. Complex intermediate (XXXII-a)is obtained as a dark solid (yield: 130 mg (70%)).

¹H-NMR (400 MHz, CD₂Cl₂): δ=1.36-1.44 (m, 2H), 1.54 (H₂O peak+m, 2H),1.58-1.62 (m, 2H), 1.79-1.87 (m, 2H), 2.63-2.64 (m, 2H), 4.70-4.72 (m,2H), 7.66-7.76 (m, 8H), 7.79-7.83 (m, 2H), 8.37-8.40 (m, 4H), 8.69 (d,2H), 9.09 (d, 2H).

h) Synthesis of Complex (XXXII)

120 mg (0.16 mmol) of complex intermediate (XXXII-a) and 116 mg (0.32mmol) of 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline aredissolved in 9 ml toluene under argon. The solution is degassed andsubsequently heated to 100° C. with stirring over night. After coolingto room temperature the solvent is removed in vacuo and the residue isfiltered through a short alumina column with cyclohexane/ethyl acetate(1:1). The solvent is again removed in vacuo and the crude product ispurified by silica column chromatography with dichloromethane/hexane4:1. The title product is obtained as yellow powder (yield: 8 mg (4%)).

HPLC-MS (positive, m/z): exact mass of C₇₁H₄₃IrN₁₂=1256.34; found 1257.5[M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.35-7.02 (br, 12H), 6.54 (t, 1H), 6.59 (t,1H), 6.65-6.74 (m, 4H), 6.83-6.91 (m, 4H), 7.25 (t, 2H), 7.35 (t, 1H),7.58 (t, 1H), 7.69-7.76 (m, 2H), 7.80-7.92 (m, 6H), 8.31-8.35 (m, 2H),8.69 (d, 1H), 8.72-8.76 (m, 2H), 9.06 (d, 1H), 9.10 (d, 1H), 9.21 (d,1H), 9.49 (d, 1H).

Synthesis Example 33 Synthesis of Complex (XXXIII) a) Synthesis ofN6,N7-diphenylquinoxaline-6,7-diamine

A suspension of 19.5 g of 6,7-dichloroquinoxaline (0.098 mol; preparedaccording to J. Chem. Soc., Perkin Trans. 1, 1999, 803), 20.2 g aniline(0.22 mol) and 25.2 g sodium tert-butoxide (0.26 mol) in 300 ml ofanhydrous toluene is degassed by cooling down to −70° C. in a dryice/acetone bath under vacuum and backfilling with argon (repeated threetimes). Then 1.07 g (2 mmol) of BrettPhos ligand[=2-(dicyclohexylphosphino)3,6-dimethoxy-2′,4′,6′-triisopropyl-1,1′-biphenyl,CAS No. 1070663-78-3] and 1.60 g (2 mmol) of BrettPhos-Pd-G3palladacycle{=[(2-di-cyclohexylphosphino-3,6-dimethoxy-2′,4′,6′-triisopropyl-1,1′-biphenyl)-2-(2′-amino-1,1′-biphenyl)]palladium(II)methanesulfonate methanesulfonate, CAS No. 1470372-59-8} are added anddegassing repeated. The thick suspension is heated for 18 hours at 100°C. (propeller stirrer), cooled to room temperature, filtered (veryslow), and rinsed with ca. 200 ml of dichloromethane. The filtrate isacidified with 10% aqueous hydrogen chloride (100 ml) and theprecipitated salt is filtered and rinsed with water. The red-brown solidis taken up in 350 ml of dichloromethane and stirred during 30 min with250 ml of saturated aqueous sodium hydrogen carbonate. The organic phaseis separated, extracted with water first, then 1% aqueous sodium cyanidesolution, followed by water (3×), dried over magnesium sulfate, andconcentrated under vacuum. The crude product is purified bychromatography (1.1 kg neutral aluminum oxide, heptane/ethyl acetate1:1) to give the title product as a yellow-brown solid (yield: 18.6 g(61%)).

¹H-NMR (300 MHz, CDCl₃): δ=8.57 (s, 2H), 7.79 (s, 2H), 7.37 (m, 4H),7.19 (m, 4H), 7.10 (m, 2H), 6.03 (s, 2H).

b) Synthesis of 1,3-diphenylimidazo[4,5-g]quinoxalin-3-iumtetrafluoroborate

A suspension of 18.64 g of N6,N7-diphenylquinoxaline-6,7-diamine (0.06mol) and 6.38 g of ammonium tetrafluoroborate (0.06 mol) in 190 mltriethyl orthoformate is heated for six hours at a temperature of100-122° C. in a reactor fitted with a Dean-Stark separator andcondenser. After cooling to room temperature, the precipitated productis filtered and rinsed successively with cold triethyl orthoformate andheptane, then dried under vacuum. The title product is obtained as ared-brown solid (yield: 20.64 g (84%)).

¹H-NMR (300 MHz, d₆-DMSO): ·=10.94 (s, 1H), 9.18 (s, 2H), 8.63 (s, 2H),8.08 (m, 4H), 7.85 (m, 4H).

c) Synthesis of Complex Intermediate (XXXIII-a)

9.46 g (23.1 mmol) of1,3-Diphenyl-imidazo[4,5-g]quinoxalinium-tetrafluoroborate and 7.75 g(11.5 mmol) of μ-chloro-1,5-cyclopentadiene-iridium(I) dimer aresuspended in 310 ml of toluene. The suspension is heated to 60° C. 46.1ml of a 0.5M (23.1 mmol) solution of potassium bis(trimethylsilyl)amidein toluene are added within 25 minutes to the reaction mixture andstirred at 60° C. for 15 min. 15 g of Diatomaceous earth are added tothe reaction mixture at 60° C. The solid is filtered off and washed fourtimes with 25 ml of warm toluene (50-60° C.). The filtrate isconcentrated under vacuum. The solid is stirred in 90 ml ethanol for onehour, then filtered off, washed three times with 10 ml of ethanol, andthen washed three times with 10 ml n-pentane, and dried under vacuum ina drying cabinet at 60° C. for 17 hours. 10.8 g dark brown solid areobtained.

¹H-NMR (500 MHz, CD₂Cl₂): δ [ppm]=1.34 (mc; 2H), 1.42-1.56 (m; 4H), 1.73(mc; 2H), 2.63 (mc; 2H), 4.52 (mc; 2H), 7.67 (mc; 6H), 7.94 (mc; 2H),8.13 (mc; 4H), 8.80 (mc; 2H).

d) Synthesis of Complex (XXXIII)

2.16 g (2.95 mmol) of complex intermediate (XXXIII-a) and 4.35 g (11.8mmol) 2-ethoxy-1,3-diphenyl-2H-imidazo[4,5-b]quinoxaline are added to 70ml of chlorobenzene. The suspension is heated to 125° C. and is held atthat temperature for 22 hours. After cooling the reaction mixture toroom temperature the precipitate is filtered off. The filtrate isevaporated to dryness in an attenuated vacuum. The solid is washed threetimes with 2 ml of chlorobenzene, then three times with 3 ml n-pentane,and dried under vacuum in a drying cabinet at 60° C. for 3 hours. 0.33 gbrown solid are obtained. The solid is dissolved in 90 ml ofdichloromethane and purified by MPLC with the CombiFlash Companion(silica gel, dichloromethane/methanol 98:2). The obtained solid (0.26 g)is heated in 5 ml of acetonitrile. The suspension is filtered hot. Theprecipitate is washed twice with 1 ml of hot acetonitrile each, and thenwashed twice with 1 ml of hot THF, and dried under vacuum in a dryingcabinet at 60° C. for 17 hours. 0.21 g yellow solid are obtained whichare recrystallized from chlorobenzene. The filtered precipitation iswashed with a small amount of chlorobenzene and n-pentane. The solid isdried under vacuum in a drying cabinet at 60° C. for 65 hours, givingthe title product as a yellow solid (yield: 80 mg).

¹H-NMR (400 MHz, CD₂Cl₂): δ [ppm]=6.40 (mc; 2H), 6.55-6.85 (m; 15H),7.11 (mc; 1H), 7.24 (mc; 4H), 7.40 (mc; 2H), 7.74 (mc; 2H), 7.79-7.90(m; 5H), 8.20 (mc; 1H), 8.33 (mc; 2H), 8.76 (mc; 1H), 8.82 (mc; 1H),8.89 (mc; 1H), 9.02 (mc; 1H), 9.08 (mc; 1H).

Synthesis of Comparative Examples Comparative Synthesis Example 1Synthesis of Comparative Complex (CC-1)

Described in WO2014/147134

The synthesis of the comparative complex CC-1 is described inWO2014/147134 (example BE-12).

Comparative Synthesis Example 2 Synthesis of Comparative Complex (CC-2)

9.12 g (22.3 mmol) of 1,3-diphenylbenzo[f]benzimidazol-3-iumtetrafluoroborate in 200 ml dioxane are three times evacuated andbackfilled with argon. 53.6 ml (26.8 mmol) of potassiumbis(trimethylsilyl)amide solution (KHMDS, 0.5M in toluene) are added atroom temperature within 15 minutes. The orange-red-suspension is heatedup to 67° C. and treated with 1.50 g (2.23 mmol) ofchloro(1,5-cyclooctadiene)iridium(I) dimer, followed by heating at 101°C. during 22 hours. The reaction mixture is cooled down to 80° C. andfiltered. The solid is washed with dioxane and acetone, followed bydrying under vacuum. The solid is suspended in 1.5 L of dichloromethaneand filtered through a 5 cm layer of silica gel, followed by rinsing thesilica gel layer with 200 ml of dichloromethane. The combined eluentsare treated with 200 ml of acetone and concentrated under vacuum until asuspension formed. The suspension is filtered, the solid washed withacetone, followed by drying under vacuum, giving the title product as alight yellow solid (yield: 3.34 g (65%)).

APCI-LC-MS (positive, m/z): exact mass of C₆₉H₄₅IrN₆=1150.33; found1151.4 [M+1]⁺.

¹H-NMR (400 MHz, CD₂Cl₂): δ=6.36 (br. d, 6H), 6.61-6.67 (m, 3H), 6.69(dd, 3H), 6.76 (td, 3H), 6.82 (br. d, 3H), 6.87 (s, 3H), 7.18-7.25 (m,3H), 7.37-7.48 (m, 6H), 7.50-7.57 (m, 3H), 7.69 (d, 3H), 8.14 (d, 3H),8.18 (d, 3H), 8.59 (s, 3H).

Comparative Synthesis Example 3 Synthesis of Comparative Complex (CC-3)a) Synthesis of N2-methyl-N3-phenyl-quinoxaline-2,3-diamine

A suspension of 22.60 g (0.227 mol) 2-methylamino-3-chloro-quinoxalinewhich has been synthetized according to DE 1135471, 16.37 g (0.176 mol)aniline, and 1.06 g (0.006 mol) HBr 48% are dissolved in 375 mldiethylenglycol by heating to 170° C. The reaction mixture is held atthat temperature for 15 min. After cooling the reaction mixture to roomtemperature the solid is filtered off, and then shortly stirred in 300ml water. The solid is filtered off and dried in a vacuum drying cabinetat 60° C. 15.69 g solid are obtained.

MALDI-MS (positive, m/z): exact mass of C₄₈H₃₃IrN₁₂=970.26; found 970[M+H]⁺

¹H-NMR (400 MHz, D₆-DMSO): δ [ppm]=3.22 (s; 3H), 7.13 (mc; 1H), 7.43(mc; 4H), 7.60 (mc; 1H), 7.85 (mc; 1H), 8.07 (mc; 2H), 10.11 (s; 1H,broad), 10.64 (s; 1H, very broad).

b) Synthesis of 2-ethoxy-1-methyl-3-phenyl-2H-imidazo[4,5-b]quinoxaline

A solution of 11.80 g (47.1 mmol)N2-methyl-N3-phenyl-quinoxaline-2,3-diamine in 224 ml triethylortho-formiate is stirred at 90° C. for 24 h. After cooling the reactionmixture to 60° C. the solution is evaporated to dryness in an attenuatedvacuum until 70° C. The residue is stirred in diethylether for 1 h. Theprecipitate is filtered off, washed with diethylether, and is dried in avacuum drying cabinet at 60° C. 10.5 g solid are obtained

¹H-NMR (400 MHz, CD₃CN): δ [ppm]=1.06 (t; 3H), 3.18 (s; 3H), 3.27 (q;2H), 6.90 (s; 1H), 7.24 (mc; 1H), 7.32 (mc; 2H), 7.50 (mc; 2H), 7.56(mc; 1H), 7.60 (mc; 1H), 8.10 (mc; 2H).

¹H-NMR (400 MHz, CD₃CN): · [ppm]=1.06 (t; 3H), 3.18 (s; 3H), 3.27 (q;2H), 6.90 (s; 1H), 7.24 (mc; 1H), 7.32 (mc; 2H), 7.50 (mc; 2H), 7.56(mc; 1H), 7.60 (mc; 1H), 8.10 (mc; 2H).

c) Synthesis of Comparative Complex (CC-3)

A solution of 10.40 g (33.95 mmol) of2-ethoxy-1-methyl-3-phenyl-2H-imidazo[4,5-b]quinoxaline and 2.97 g (4.42mmol) μ-chloro-cyclooctadien-iridium dimer in 130 ml o-dichlorobenzeneis heated to 150° C. and stirred at that temperature for 21 h. Aftercooling the reaction mixture to room temperature the precipitate isfiltered off, washed with o-dichlorobenzene, and dried in a vacuumdrying cabinet at 60° C. The solid is stirred in hot ethanol for 30 min.After cooling the suspension to room temperature the precipitate isfiltered off, washed with n-pentane, and is dried in a vacuum dryingcabinet at 80° C. 8.60 g beige solid are obtained. 1.88 g of the beigesolid are treated with 20 ml 1M aqueous HCl in 190 ml ethylmethylketone.The reaction mixture is heated at 70° C. for 29.5 h. After cooling thereaction mixture to 60° C. it is filtered. The residue is washed withn-pentane and dried at 60° C. in a vacuum drying cabinet. 1.80 g darkyellow solid is obtained. The solid is heated in 35 ml chlorobenzeneunder reflux for 1 h. The suspension is cooled to 110° C. and filtered.The residue is washed with warm chlorobenzene and then with n-pentane.The solid is dried at 150° C. at 6.5×10⁻² mbar for 7 h. 1.25 g (66% oftheory in two steps) yellow solid are obtained.

¹H-NMR (400 MHz, CD₂Cl₂): δ [ppm]=3.59 (s; 9H), 6.55 (mc; 3H), 6.79 (mc;3H), 7.16 (mc; 3H), 7.80 (mc; 6H), 8.10 (mc; 3H), 8.30 (mc; 3H), 8.93(mc; 3H).

II. Photoluminescence Examples Photoluminescence Examples A

Determination of the Photoluminescence Spectra (2% Film in PMMA Matrix)

The photoluminescence (PL) spectra of the complexes are measured on thinpolymer films doped with the respective complexes. The thin films areprepared by the following procedure: a 10%-w/w polymer solution is madeby dissolving 1 g of the polymer “PMMA 6N” (Evonik) in 9 g ofdichloromethane, followed by stirring for one hour. 2 mg of therespective complexes are added to 0.098 g of the PMMA solution, andstirring continued for one minute. The solutions are casted bydoctor-blading with a film applicator (Model 360 2082, Erichsen) with a60 μm gap onto quartz substrates providing thin doped polymer films(thickness ca. 6 μm). The PL spectra and quantum-yields (Q.Y.) of thesefilms are measured with the integrating-sphere method using the AbsolutePL Quantum Yield Measurement System (Hamamatsu, Model C9920-02)(excitation wavelength: 370 nm).

Determination of the Lifetime of Luminescence τ_(v)

The lifetime (τ_(v)) of the luminescence of the complexes in theprepared films are measured by the following procedure: For excitationof the emission a sequence of short laser pulses (THG Nd-YAG, 355 nm, 1nsec pulse length, 1 kHz repetition rate) is used. The emissions aredetected by the time-resolved photon-counting technique in themulti-channel scaling modus using a combination of photomultiplier,discriminator and a multiscaler card (FAST ComTec GmbH, Model P7888).

The PL Q.Y., λ_(max), CIE x, y, and τ_(v) values of thephotoluminescence measurements are included in the following tables.

PL λ_(max) τ_(V) Cpd. Formula Q.Y. (nm) CIE x, y (μs)  I

84% 543 0.39, 0.58  1.7 II

88% 539 0.37, 0.59 

Photoluminescence Examples B

Determination of the Photoluminescence Spectra

The photoluminescence (PL) spectra of the complexes are measured on thinpolymer films doped with the respective complexes. The thin films areprepared by the following procedure: a 10%-w/w polymer solution is madeby dissolving 1 g of the polymer “PMMA 6N” (Evonik) in 9 g ofdichloromethane, followed by stirring for one hour. 2 mg of therespective complexes are added to 0.098 g of the PMMA solution, andstirring continued for one minute. The solutions are casted bydoctor-blading with a film applicator (Model 360 2082, Erichsen) with a60 μm gap onto quartz substrates providing thin doped polymer films(thickness ca. 6 μm). The PL spectra and quantum-yields (Q.Y.) of thesefilms are measured with the integrating-sphere method using the AbsolutePL Quantum Yield Measurement System (Hamamatsu, Model C9920-02)(excitation wavelength: 400 nm).

Determination of the Lifetime of Luminescence τ_(v)

The lifetime (τ_(v)) of the luminescence of the complexes in theprepared films are measured by the following procedure: For excitationof the emission a sequence of short laser pulses (THG Nd-YAG, 355 nm, 1nsec pulse length, 1 kHz repetition rate) is used. The emissions aredetected by the time-resolved photon-counting technique in themulti-channel scaling modus using a combination of photomultiplier,discriminator and a multiscaler card (FAST ComTec GmbH, Model P7888).

The PL Q.Y., λ_(max), CIE x, y color coordinates, full width at halfmaximum (FWHM) of the emission spectra, and τ_(v) values of thephotoluminescence measurements in the iridium complex doped PMMA filmsare included in the following tables. Data of all emitters are givenfrom PL measurements of 2% films in PMMA matrix, except for compound IV,of which the data are given from a PL measurement of a 1% film in PMMAmatrix.

PL λ_(max) FWHM τ_(V) Cpd. Formula Q.Y. (nm) CIE x, y (nm) (μs) I

84% 543 0.39, 0.58  80 1.7 II

88% 539 0.37, 0.59  83 2.8 IV O795

92% 521 0.32, 0.62  73 2.4 V O35191

95% 531 0.34, 0.61  78 2.1 VIa

86% 542 0.39, 0.59  86 1.8 VII

90% 534 0.35, 0.61  76 2.1 VIII

89% 539 0.38, 0.59  79 1.8 X

84% 546 0.40, 0.57  85 1.1 XI

82% 549 0.41, 0.57  85 1.4 XIII

89% 531 0.35, 0.61  79 2.2 XIV

92% 530 0.34, 0.61  78 1.9 XV

88% 533 0.35, 0.61  78 1.9 XVI

87% 542 0.39, 0.59  80 2.3 XVII

95% 527 0.33, 0.61  76 2.4 XVIII

89% 530 0.33, 0.61  79 2.3 XIX

95% 536 0.35, 0.61  79 1.9 XX

91% 538 0.37, 0.60  80 1.4 XXI

89% 544 0.39, 0.59  81 1.2 XXII

79% 551 0.42, 0.56  82 1.3 XXIII

89% 544 0.40, 0.58  82 1.5 XXIV

94% 540 0.38, 0.59  81 1.5 XXV

87% 523 0.32, 0.62  74 2.6 XXVI

86% 553 0.43, 0.56  90 1.2 XXVII

90% 535 0.36, 0.60  79 2.3 XXVIII

87% 542 0.38, 0.59  84 2.9 XXIX

84% 548 0.40, 0.57  85 1.1 XXX

91% 536 0.36, 0.60  79 1.7 XXXI

95% 525 0.33, 0.62  74 3.0 XXXII

91% 525 0.33, 0.62  75 3.0

As evident from the above table, the complexes of the present inventionshow an emission in the green to yellow-green area, with very highabsolute PL quantum efficiency values Q.Y., with short lifetimes ofluminescence τ_(v), which are as low as down to 1.1 μs.

Comparative Examples Comparative Example 1

The PL Q.Y., λ_(max), CIE x, y color coordinates and τ_(v) values of thephotoluminescence measurements of complexes IV and CC-1 are included inthe following table. Data of both complexes are given from PLmeasurements of 1% films of the respective complexes in PMMA matrix.Synthesis of the comparative complex CC-1 is described in WO2014/147134(example BE-12). überall weg

PL λ_(max) τ_(V) Cpd. Formula Q.Y. (nm) CIE x, y (μs) IV

92% 521 0.32, 0.62  2.4 CC-1

86% 473 0.14, 0.20  6.0

As is evident from the above table, the green emitting inventive metalcarbene complex IV shows a factor of 2.5 shorter (improved) lifetime ofthe luminescence τ_(v) in comparison to comparative compound CC-1.

The inventive metal carbene complex IV with an imidazo-quinoxalinecarbene ligand shows a green emission with CIE x,y color coordinates of(0.32, 0.62), with very high absolute PL quantum efficiency Q.Y. of 92%close to the theoretical limit, and a very good (=short) lifetime of theluminescence τ_(v) of 2.4 μs. The comparative complex CC-1 with acyclohexane unit attached to the imidazo-pyrazine unit, instead of thebenzene unit, as in the inventive complex IV, shows a blue emission withCIE x,y color coordinates of (0.14, 0.20), with a high absolute PLquantum efficiency Q.Y. of 86%, but a lifetime of luminescence τ_(v)which is elongated to 6.0 μs.

The short lifetime of luminescence τ_(v) of the inventive complex IV issurprising in respect to the elongated lifetime of luminescence τ_(v) ofthe comparative complex CC-1. As is evident from the above table,surprisingly, despite the attached benzene ring at the imidazo-pyrazineunit of the carbene ligand in complex IV the lifetime of theluminescence τ_(v) is very good (=short), although the attached cyclicalkane unit to the imidazo-pyrazine unit of the carbene ligand incomparative complex CC-1 is leading to a long lifetime of theluminescence τ_(v).

Comparative Example 2

The PL Q.Y., λ_(max), CIE x, y color coordinates and τ_(v) values of thephotoluminescence measurements of complexes IV and CC-2 are included inthe following table. Data of both complexes are given from PLmeasurements of 1% films of the respective complexes in PMMA matrix.Synthesis of the comparative complex CC-2 is described in Comparativesynthesis Example 2.

PL λ_(max) τ_(V) Cpd. Formula Q.Y. (nm) CIE x, y (μs) IV

92% 521 0.32, 0.62  2.4 CC-2

85% 512 0.32, 0.62  105

As is evident from the above table, the green emitting inventive metalcarbene complex IV shows a factor of 44 shorter (improved) lifetime ofthe luminescence τ_(v) in comparison to green emitting comparativecompound CC-2, at the same CIE x,y color coordinates.

The inventive metal carbene complex IV with an imidazo-quinoxalinecarbene ligand shows a green emission with CIE x,y color coordinates of(0.32, 0.62), with very high absolute PL quantum efficiency Q.Y. of 92%close to the theoretical limit, and a very good (=short) lifetime of theluminescence τ_(v) of 2.4 μs. The comparative complex CC-2 with animidazo-naphthalene carbene ligand instead shows a green emission withthe same CIE x,y color coordinates, with a high absolute PL quantumefficiency Q.Y. of 85%, but a lifetime of luminescence τ_(v) which isextremely elongated to 105 μs, compared to 2.4 μs in the case of theinventive complex IV.

The short lifetime of luminescence τ_(v) of the inventive complex IV issurprising in respect to the highly elongated lifetime of luminescenceτ_(v) of CC-2.

As is evident from the above tables, a carbene metal complex is emittingin the green to yellow-green area, with a very high Q.Y. close to thetheoretical limit, and together with a short luminescence τ_(v) if aninventive imidazo-quinoxaline carbene ligand is used.

III Device Examples

Production of an OLED (General Procedure)

The ITO substrate used as the anode is cleaned first by rinsing withisopropanol. To eliminate possible organic residues, the substrate isexposed to a continuous ozone flow in an UV ozone oven for a further 20minutes. This treatment also improves the hole injection properties ofthe ITO.

Thereafter, the organic materials specified below are applied by vapordeposition to the cleaned substrate at a pressure of about 10⁻⁷-10⁻⁹mbar and at a rate of approx. 0.5-5 nm/min. The hole conductor andexciton blocker applied to the substrate is Ir(DPBIC)₃ (devices 1 to 3).Depending on the emissive layer thickness and thus for adjusting theoptical cavity, the hole conductor has a thickness of 50 or 55 nm, theblocker has a thickness of 10 nm. The hole conducting layer is dopedwith MoO_(x) (50 wt.-%:50 wt.-%) to improve the conductivity.

(for preparation of Ir(DPBIC)₃ see Ir complex (7) in the applicationWO2005/019373).

Subsequently, a mixture of emitter, Ir(DPBIC)₃ and a host material (theemitter, the host material (SH-1 or SH-2) and the relative amounts in %by weight are given in the specific device examples) is applied by vapordeposition with a thickness of 30 or 40 nm (devices 1 to 3).Subsequently, the host material is applied by vapor deposition with athickness of 5 nm as an exciton and hole blocker.

Host Material:

SH-1:

(compound “3-1” in “Synthetic example 2” in US2009/066226)

SH-2:

(compound I-1, on page 7 and 78, in US2011/0006670)

Next, as an electron transporter, a mixture of Liq and ETM (ETM-1 asspecified in the specific device examples) (50 wt.-%:50 wt.-%) isapplied by vapor deposition in a thickness of 30 nm; then a 4 nm KFlayer is applied; and finally a 100 nm-thick Al electrode is applied.The whole device is encapsulated by attaching a glass lid under inertnitrogen atmosphere with an UV curable adhesive with very low watervapor permeation rate.

Electron Transport Material:

ETM-1:

(compound A1 in WO2011/157779; compound A-10 in WO2006/128800)

To characterize the OLED, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer. The lifetime LT₉₅ of the diode is definedby the time taken for the luminance to fall to 95% of its initial value.The lifetime measurement is carried out at a constant current. TheCIE_(x,y) coordinates are extracted from the spectra according to CIE1931 as known in the state-of-the-art.

For the different emitters, host materials and electron transportmaterials in the above-described OLED structure, the followingelectrooptical data are obtained:

All data are obtained at 1000 cd/m², lifetime data is taken at 4000cd/m² initial luminance.

Device 1:

50 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—40 nmemitter/SH-1/Ir(DPBIC)₃ (15:80:5)—5 nm SH-1—30 nm ETM-1:Liq (50:50)—4 nmKF—100 nm Al

Device 2:

55 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—30 nmemitter/SH-1/Ir(DPBIC)₃ (15:80:5)—5 nm SH-1—35 nm ETM-1:Liq (50:50)—4 nmKF—100 nm Al

Device 3:

55 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—30 nmemitter/SH-2/Ir(DPBIC)₃ (15:80:5)—5 nm SH-2—35 nm ETM-1:Liq (50:50)—4 nmKF—100 nm Al

Synthesis of the comparative complex CC-3 is described in ComparativeSynthesis Example 3.

TABLE 5 λ_(max)/ Voltage CurrEff LumEff EQE FWHM Emitter [V] [cd/A][Im/W] [%] CIE x, y (nm) LT₉₅ (h) Dev. 1 IV 5.13 66.9 41.0 18.2 0.34,0.62 528/70 360 Dev. 3 IV 4.56 61.1 42.1 16.7 0.33, 0.62 526/71 500 Dev.1 V 5.81 72.0 38.9 19.5 0.34, 0.62 528/71 370 Dev. 2 V 4.82 72.6 47.319.7 0.34, 0.62 529/70 310 Dev. 2 XX 4.26 72.9 53.8 19.9 0.38, 0.59543/74 380 Dev. 3 XXVII 4.60 65.5 44.8 17.7 0.37, 0.61 537/74 340 Dev. 3XXIX 4.42 64.1 45.6 18.0 0.41, 0.58 549/77 250 Dev. 3 XVIII 5.32 71.242.0 19.3 0.35, 0.61 531/76 230 Dev. 3 XXVI 4.20 58.6 43.8 16.8 0.42,0.56 554/78 160 Dev. 1 VII 5.53 57.8 32.8 15.8 0.36, 0.61 534/75 350Dev. 1 XXI 5.75 68.9 37.7 18.8 0.38, 0.60 541/73 130 Dev. 1 VIa 5.7956.3 30.5 15.2 0.38, 0.60 537/71 100 Dev. 3 CC-3 4.71 60.8 40.5 16.80.36, 0.60 532/78 2

As is evident from the above table, the inventive green emitting metalcomplex IV shows much improved device lifetime LT₉₅ against comparativegreen emitting complex CC-3 in the same device setup 3. LT₉₅ is improvedby a factor of 250, at otherwise comparable device characteristics, andat highly comparable emission (λ_(max) and CIE x,y).

As is also evident from the above table, the inventive metal carbenecomplexes show a green to yellow-green emission color at remarkable highexternal quantum efficiencies (EQEs) and high current efficiencies. Inthose tables, all EQEs are calculated from the measured luminance inforward direction under the assumption of Lambertian emission. As shownabove, typical examples of inventive emitters demonstrate remarkablehigh device stability, as shown for devices 1, 2, or 3, respectively.

The device setups 4 and 5 are similar to device setups 1 to 3, butdemonstrate optimized setups, including different emitterconcentrations, different Ir(DPBIC)₃ concentration, or use of adifferent host SH-1 or SH-2.

Optimized Setups

Device 4:

50 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—40 nmemitter/SH-2/Ir(DPBIC)₃ (15:80:5)—5 nm SH-2—30 nm ETM-1:Liq (50:50)—4 nmKF—100 nm Al

Device 5:

55 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—30 nmemitter/SH-1/Ir(DPBIC)₃ (25:65:10)—5 nm SH-1—35 nm ETM-1:Liq (50:50)—4nm KF—100 nm Al

TABLE 6 Volt- λ_(max)/ Emit- age CurrEff LumEff EQE CIE FWHM LT₉₅ ter[V] [cd/A] [Im/W] [%] x, y (nm) (h) Dev. IV 5.96 56.8 29.9 15.5 0.34,527/74 670 4 0.62 Dev. XX 4.08 66.1 50.9 18.3 0.40, 545/77 610 5 0.58

As is evident from the above table, for example, LT₉₅ of both inventivemetal complexes IV and XX is further increased to over 600 h by usingadapted device setups 4 or 5, respectively.

For a comparison of the influence of the emission layer thickness on thedriving voltage, the following results in device 6 of the inventiveemitter example V are shown.

Device 6:

50 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—20-40 nmV/SH-1/Ir(DPBIC)₃ (20:75:5)—3 nm SH-1—30 nm ETM-1:Liq (50:50)—4 nmKF—100 nm Al

TABLE 7 Emis- sive layer λ_(max)/ thick- Voltage CurrEff LumEff EQE FWHMLT₉₅ ness [V] [cd/A] [Im/W] [%] CIE x, y (nm) (h) 20 nm 3.55 67.9 60.018.6 0.33, 526/67 230 0.63 30 nm 4.34 69.3 50.2 18.8 0.33, 527/68 4050.62 40 nm 5.19 69.6 42.1 18.9 0.34, 530/72 430 0.62

As is evident from the above table, a voltage drop from 5.19 eV to 3.55eV can be observed when decreasing the layer thickness from 40 nm to 20nm, at the same time leaving all other initial performance parametersalmost unchanged.

Additional results in device setup 7 are demonstrating the same findingsusing the inventive emitter example IV.

Device 7:

60-45 nm Ir(DPBIC)₃:MoO₃ (50:50)—10 nm Ir(DPBIC)₃—20-50 nmIV/SH-1/Ir(DPBIC)₃ (20:75:5)—5 nm SH-1—40-25 nm ETM-1:Liq (50:50)—4 nmKF—100 nm Al

TABLE 8 Emis- sive layer λ_(max)/ thick- Voltage CurrEff LumEff EQE CIEFWHM LT₉₅ ness [V] [cd/A] [Im/W] [%] x, y (nm) (h) 20 nm 3.79 64.6 53.617.6 0.33, 527/71 250 0.62 30 nm 4.51 64.7 45.1 17.6 0.33, 528/72 3200.62 40 nm 5.35 66.1 38.8 17.9 0.33, 527/70 250 0.62 50 nm 6.06 66.534.5 18.1 0.34, 527/71 220 0.62

By changing molecular properties of the inventive compounds it ispossible to directly influence the driving voltage of the OLED devices.This can be done either by modification of the electron affinity whichwill affect the electron transport property of the emissive layer sincethe emitter acts as a deep trap (see data in the following table 9). Orthe number of electron transporting ligands of the inventive compound ismodified which leads to altered electron transporting properties betweenthe emitter molecules (see data in the following table 10).

Results in the following tables are achieved using the inventivecompounds XVIII, XXVI, XX, respectively, in device setup 7 with 20% ofemitter concentration and 30 nm emissive layer thickness. ElectronAffinities (EA) are calculated based on geometries of neutral andanionic molecules from density functional theory with the b-p86functional and a SVp basis set in the gas phase. EA is then obtained asthe energy difference between the single point energy of the anionic andneutral state, both evaluated within the Conductor Like Screening Model(COSMO) employing a dielectric constant of 4.5 using the b-p86functional and a TZVp basis set. All calculations are performed usingthe TURBOMOLE package. The number of electron transporting ligands isobtained by analyzing the LUMO distribution from the gas phasecalculation of the neutral molecule.

TABLE 9 # of e- EA transporting Voltage Emitter [eV] ligands [V] XVIII2.53 1 5.13 XXVI 2.30 1 3.98

TABLE 10 # of e- EA transporting Voltage Emitter [eV] ligands [V] XVIII2.53 1 5.13 XX 2.62 2 4.42

As is evident from the above table, starting from a higher voltage of5.13 V for XVIII, it is possible to reduce the voltage down to <4 V byreduction of the EA, and thus reduction of the electron trap depth, forinventive compound XXVI. By just looking at the EA of the inventivecompound XX one would now expect an even higher voltage compared toXVIII, since the trap depth is even larger for electrons. However, thedriving voltage can be reduced to 4.42 eV by increasing the number ofe-transporting ligands from one to two and thus increasing thepropability for an electron to hop between the emitter molecules.

FIGURE

FIG. 1 shows a comparison of the emission spectrum of OLED device 3comprising inventive complex (IV) compared with the emission spectrum ofOLED device 3 comprising comparative complex (CC-3).

In FIG. 1:

The Y-axis shows the EL intensity in arbitrary units (a.u.) and theX-axis shows the wavelength in nm. The dotted line shows the emissionspectrum of the OLED comprising inventive complex (IV) and thecontinuous line shows the emission spectrum of the OLED comprisingcomparative complex (CC-3).

The invention claimed is:
 1. A metal carbene complex, comprising atleast one ligand of formula (A)

wherein Z is NR^(x); R^(x) is

R¹, R², R³ and R⁴ are independently of each other hydrogen; aC₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₁₂cycloalkyl group, whichcan optionally be substituted by at least one substituent E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one of O, S and NR⁶⁵ and/or substituted by at least onesubstituent E; a C₆-C₁₄ aryl group, which can optionally be substitutedby at least one substituent G; a NR⁶⁵—C₆-C₁₄aryl group, which canoptionally be substituted by at least one substituent G; a heteroarylgroup comprising 3 to 11 ring atoms, which can optionally be substitutedby at least one substituent G, interrupted by at least one of O, S, Nand NR⁶⁵; or a NR⁶⁵-heteroaryl group, comprising 3 to 11 ring atoms,which can optionally be substituted by at least one substituent G,interrupted by at least one of O, S, N and NR⁶⁵; a halogen atom; aC₁-C₁₈haloalkyl group; CN; or SiR⁸⁰R⁸¹R⁸²; or R¹ and R², R² and R³ or R³and R⁴ form together a ring

wherein A²¹, A^(21′), A²², A^(22′), A²³, A^(23′), A^(24′) and A²⁴ areindependently of each other hydrogen, a C₁-C₄alkyl group, aC₃-C₆cycloalkyl group, or a fluoroC₁-C₄alkyl group; R⁵ and R⁶ areindependently of each other hydrogen; a C₁-C₁₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one of O, S andNR⁶⁵ and/or substituted by at least one substituent E; a C₆-C₁₄arylgroup, which can optionally be substituted by at least one substituentG; a —NR⁶⁵—C₆-C₁₄aryl group, which can optionally be substituted by atleast one substituent G; a heteroaryl group comprising 3 to 11 ringatoms, which can optionally be substituted by at least one substituentG, interrupted by at least one of O, S, N and NR⁶⁵; a halogen atom; aC₁-C₁₈haloalkyl group; CN; or SiR⁸⁰R⁸¹R⁸²; R⁷, R⁸, R⁹, R²⁷ and R²⁸ areindependently of each other hydrogen; a C₁-C₁₈alkyl group, which canoptionally be substituted by at least one substituent E and/orinterrupted by D; a C₃-C₁₂cycloalkyl group, which can optionally besubstituted by at least one substituent E; a heterocycloalkyl groupcomprising 3 to 6 ring atoms, interrupted by at least one of O, S andNR⁶⁵ and/or substituted by at least one substituent E; a C₆-C₁₄arylgroup, which can optionally be substituted by at least one substituentG; a heteroaryl group comprising 3 to 11 ring atoms, which canoptionally be substituted by at least one substituent G, interrupted byat least one of O, S, N and NR⁶⁵ a halogen atom; a C₁-C₁₈haloalkylgroup; CN; or SiR⁸⁰R⁸¹R⁸²; in addition to the groups mentioned above, R⁸may be a —NR⁶⁵—C₆-C₁₄aryl group, which can optionally be substituted byat least one substituent G; or a —NR⁶⁵-heteroaryl group comprising 3 to11 ring atoms, which can optionally be substituted by at least onesubstituent G, interrupted by at least one of O, S, N and NR⁶⁵; or R⁵and R⁶ and/or R⁸ and R⁹ together form a group of formula

wherein Z′ is N or CR′″, wherein 0 or 1 Z′ is N, X is O, S, NR⁷⁵ orCR⁷³R⁷⁴; R′″ is C₁-C₈alkyl; a is 0, 1 or 2; D is —CO—, —COO—, —S—, —SO—,—SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—, or —C≡C; E is—OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, halogen, aC₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₁-C₈haloalkyl group, or aC₁-C₈alkyl group; G is E; or an unsubstituted C₆-C₁₄aryl group; aC₆-C₁₄aryl group, which is substituted by F, C₁-C₁₈alkyl, orC₁-C₁₈alkyl, which is substituted by F and/or interrupted by O; anunsubstituted heteroaryl group comprising 3 to 11 ring atoms,interrupted by at least one of O, S, N and NR⁶⁵; or a heteroaryl groupcomprising 3 to 11 ring atoms, interrupted by at least one of O, S, Nand NR⁶⁵, which is substituted by F, unsubstituted C₁-C₁₈alkyl,SiR⁸⁰R⁸¹R⁸², or C₁-C₁₈alkyl, which is substituted by F and/orinterrupted by O; or a group of formula

wherein R^(a) is hydrogen, a C₁-C₅alkyl group, a fluoroC₁-C₄alkyl group,or a C₃-C₆cycloalkyl group; R^(e) is hydrogen, a C₁-C₅alkyl group, afluoroC₁-C₄alkyl group, or a C₃-C₆cycloalkyl group; R^(c), R^(b) andR^(d) are independently of each other hydrogen; a C₁-C₁₈alkyl group,which can optionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by G; aC₃-C₁₀heterocycloalkyl radical which is interrupted by at least one ofO, S and NR⁶⁵ and/or substituted by E; a C₆-C₂₄aryl group, which canoptionally be substituted by G; or a C₂-C₃₀heteroaryl group, which canoptionally be substituted by G; a halogen atom; C₁-C₈haloalkyl; CN; orSiR⁸⁰R⁸¹R⁸²; or R^(c) and R^(b), or R^(a) and R^(b) together form agroup of formula

wherein Z′ is N or CR′″, wherein 0 or 1 Z′ is N, X is O, S, NR⁷⁵ orCR⁷³R⁷⁴R′″ is C₁-C₈alkyl, a is 0, 1 or 2; R⁶³ and R⁶⁴ are independentlyof each other hydrogen; unsubstituted C₆-C₁₈aryl; C₆-C₁₈aryl which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; unsubstituted C₁-C₁₈alkyl;or C₁-C₁₈alkyl which is interrupted by —O—; R⁶⁵ and R⁶⁶ areindependently of each other hydrogen, an unsubstituted C₆-C₁₈aryl group;a C₆-C₁₈aryl group which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy;an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—; or R⁶⁵ and R⁶⁶ together form a five or six memberedring, R⁶⁷ is hydrogen, an unsubstituted C₆-C₁₈aryl group; a C₆-C₁₈arylgroup, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; anunsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—; R⁶⁸ is hydrogen; an unsubstituted C₆-C₁₈aryl group;a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, orC₁-C₁₈alkoxy; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; R⁶⁹ is hydrogen, an unsubstitutedC₆-C₁₈aryl; a C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl, orC₁-C₁₈alkoxy; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; R⁷⁰ and R⁷¹ are independently ofeach other an unsubstituted C₁-C₁₈alkyl group; an unsubstitutedC₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted byC₁-C₁₈alkyl; R⁷² is an unsubstituted C₁-C₁₈alkyl group; an unsubstitutedC₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted byC₁-C₁₈alkyl; R⁷³ and R⁷⁴ are independently of each other hydrogen,C₁-C₂₅alkyl, C₁-C₂₅alkyl which is interrupted by O, C₇-C₂₅arylalkyl,C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by C₁-C₁₈alkyl,C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl, which is substituted byC₁-C₁₈alkyl; R⁷⁵ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or aC₁-C₁₈alkyl group, which is interrupted by —O—; R⁸⁰, R⁸¹ and R⁸² areindependently of each other a C₁-C₂₅alkyl group, which can optionally beinterrupted by 0; a C₆-C₁₄aryl group, which can optionally besubstituted by C₁-C₁₈alkyl; or a heteroaryl group comprising 3 to 11ring atoms, which can optionally be substituted by C₁-C₁₈alkyl; and ˜ isa bonding site to the metal, wherein the metal is selected from thegroup consisting of Ir and Pt.
 2. The metal carbene complex according toclaim 1, wherein: R¹, R², R³ and R⁴ are independently of each otherhydrogen; a C₁-C₁₂alkyl group, which can optionally be substituted by atleast one substituent E and/or interrupted by D; a C₃-C₁₂cycloalkylgroup, which can optionally be substituted by at least one substituentE; a C₆-C₁₄aryl group, which can optionally be substituted by one or twogroups G; a heteroaryl group comprising 3 to 11 ring atoms, which canoptionally be substituted by one or two groups G; or a —N(phenyl)2group, which can optionally be substituted by one or two groups G-; R⁵and R⁶ are independently of each other hydrogen; a C₁-C₁₂alkyl group,which can optionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by E; or oneof R⁵ and R⁶ is a group of formula

wherein: R^(a) is hydrogen, a C₁-C₅alkyl group, a fluoroC₁-C₄alkylgroup, or a C₃-C₆cycloalkyl group; R^(e) is hydrogen, a C₁-C₅alkylgroup, a fluoroC₁-C₄alkyl group, or a C₃-C₆cycloalkyl group; R^(c),R^(b) and R^(d) are independently of each other hydrogen; a C₁-C₁₈alkylgroup, which can optionally be substituted by E and/or interrupted by D;a C₃-C₁₂cycloalkyl group, which can optionally be substituted by G; aC₆-C₁₄aryl group, which can optionally be substituted by G; aC₂-C₃₀heteroaryl group, which can optionally be substituted by G;C₁-C₈haloalkyl; or SiR⁸⁰R⁸¹R⁸²; or R^(c) and R^(b), or R^(a) and R^(b)together form a group of formula

wherein Z′ is N or CR′″, wherein 0 or 1 Z′ is N, —X is O, S, NR⁷⁵ orCR⁷³R⁷⁴R′″ is C₁-C₈alkyl and a is 0, 1 or 2; R⁷, R⁸ and R⁹ areindependently of each other hydrogen; a C₁-C₁₂alkyl group, which canoptionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by E, aC₆-C₁₄aryl group, which can optionally be substituted by one or twogroups G; a heteroaryl group comprising 3 to 11 ring atoms, which canoptionally be substituted by one or two groups G; R²⁷, R²⁸ areindependently of each other hydrogen; or a C₁-C₁₂alkyl group, which canoptionally be substituted by E and/or interrupted by D; D is —S—, or—O—; E is —OR⁶⁹, CF₃, C₁-C₈alkyl or F; G is —OR⁶⁹, CF₃ or C₁-C₈alkyl;R⁶⁵ is a phenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; and R⁶⁹ is a phenyl group, which canoptionally be substituted by one or two C₁-C₈alkyl groups; anunsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—.
 3. The metal carbene complex according to claim 1,wherein at least one of the radicals R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, andR⁹ is not hydrogen.
 4. The metal carbene complex according to claim 1,wherein R¹, R², R³ and R⁴ are independently of each other hydrogen; aC₁-C₈alkyl group, which can optionally be substituted by at least onesubstituent E; a C₃-C₆cycloalkyl group, which can optionally besubstituted by at least one substituent E; or a phenyl group, which canoptionally be substituted by one or two groups G; R⁵ and R⁶ areindependently of each other hydrogen; a C₁-C₈alkyl group, which canoptionally be substituted by at least one substituent E; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G; R⁷, R⁸ and R⁹ are independently ofeach other hydrogen; a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent E; or a C₃-C₆cycloalkyl group,which can optionally be substituted by at least one substituent E; or aphenyl group, which can optionally be substituted by one or two groupsG; R²⁷ and R²⁸ are hydrogen; E is CF₃, C₁-C₈alkyl, or F; G is CF₃ orC₁-C₈alkyl; R⁶⁵ is a phenyl group, which can optionally be substitutedby one or two C₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or aC₁-C₈alkyl group, which is interrupted by —O—; and R⁶⁹ is a phenylgroup, which can optionally be substituted by one or two C₁-C₈alkylgroups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkyl group, whichis interrupted by —O—.
 5. The metal carbene complex according to claim1, wherein R¹, R², R³ and R⁴ are independently of each other hydrogen; aC₁-C₈alkyl group; or a C₃-C₆cycloalkyl group; R⁵, R⁶, R⁷, R⁸ and R⁹ areindependently of each other hydrogen; a C₁-C₈alkyl group; or aC₃-C₆cycloalkyl group; or one of R⁵ and R⁶ is a phenyl group, which canoptionally be substituted by one or two groups G; and R²⁷ and R²⁸ arehydrogen.
 6. The metal carbene complex according to claim 1, whereineither R² and R³, or R¹ and R⁴, are hydrogen.
 7. The metal carbenecomplex according to claim 1, wherein R⁵ and R⁶ are independently ofeach other hydrogen; a C₁-C₈alkyl group; or one of R⁵ and R⁶ is a phenylgroup, which can optionally be substituted by one or two groups selectedfrom CF₃ or C₁-C₈alkyl; R⁷ and R⁹ are C₁-C₈alkyl; R⁸ is hydrogen; aC₁-C₈alkyl group; or a phenyl group, which can optionally bepara-substituted by one group selected from CF₃ or C₁-C₈alkyl; and R²⁷and R²⁸ are hydrogen.
 8. The metal carbene complex according to claim 1,wherein R⁵ is hydrogen; a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent selected from CF₃, C₁-C₈alkyland F; a C₃-C₆cycloalkyl group, which can optionally be substituted byat least one substituent selected from CF₃, C₁-C₈alkyl and F; or aphenyl group, which can optionally be substituted by one or two groupsselected from CF₃ and C₁-C₈alkyl; R⁶ and R⁸ are identical and selectedfrom the group consisting of a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent selected from CF₃, C₁-C₈alkyland F; a C₃-C₆cycloalkyl group, which can optionally be substituted byat least one substituent selected from CF₃, C₁-C₈alkyl and F; and aphenyl group, which can optionally be substituted by one or two groupsselected from CF₃ and C₁-C₈alkyl; R⁷ and R⁹ are hydrogen; wherein R⁵ andR⁶ are not at the same time a phenyl group, which can optionally besubstituted by one or two groups selected from CF₃ and C₁-C₈alkyl; andR²⁷ and R²⁸ are hydrogen.
 9. The metal carbene complex according toclaim 1, wherein R⁷, R⁸ and R⁹ are hydrogen; R⁶ is hydrogen; and R²⁷ andR²⁸ are hydrogen.
 10. The metal carbene complex according to claim 1,having the following formula (II)

wherein M is Pt or Ir; wherein if M is Ir, m is 1, 2, or 3; o is 0, 1,or 2; and the sum of m+o is 3; wherein when o=2, the ligands L may bethe same or different; and when m is 2 or 3, the m carbene ligands maybe the same or different; wherein if M is Pt, m is 1, or 2; o is 0, or1; and the sum of m+o is 2; wherein when m is 2, the m carbene ligandsmay be the same or different; and L is a monoanionic bidentate ligand.11. The metal carbene complex according to claim 10, wherein L is agroup of formula

wherein the radicals R¹⁰, R¹², R¹³, R¹⁶, R¹⁷, R¹⁸ and R¹⁹ are—in eachcase—independently of each other a C₁-C₁₈alkyl group, which canoptionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one heteroatom selected from —O—, —S— and —NR⁶⁵—, optionallybearing at least one substituent E; a halogen atom; C₁-C₈haloalkyl; CN;or SiR⁸⁰R⁸¹R⁸²; or one radical R¹⁰ and/or one radical R¹²; one radicalR¹³ and/or one radical R¹²; one radical R¹⁶ and/or one radical R¹⁷; oneradical R¹⁸ and/or one radical R¹⁹ is a group of formula

wherein R^(a) is hydrogen, a C₁-C₈alkyl group, a fluoroC₁-C₄alkyl group,or a C₃-C₆cycloalkyl group; R^(e) is hydrogen, a C₁-C₈alkyl group, afluoroC₁-C₄alkyl group, or a C₃-C₆cycloalkyl group; R^(c), R^(b) andR^(d) are independently of each other hydrogen; a C₁-C₁₈alkyl group,which can optionally be substituted by E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by G; aC₃-C₁₀heterocycloalkyl radical which is interrupted by at least one ofO, S and NR⁶⁵ and/or substituted by E; a C₆-C₂₄aryl group, which canoptionally be substituted by G; a C₂-C₃₀heteroaryl group, which canoptionally be substituted by G; a halogen atom; CN; or SiR⁸⁰R⁸¹R⁸²; ortwo adjacent radicals R¹⁰ and/or two adjacent radicals R¹²; two adjacentradicals R¹³ and/or two adjacent radicals R¹²; two adjacent radicals R¹⁶and/or two adjacent radicals R¹⁷; or two adjacent radicals R¹⁹; or R^(c)and R^(b), or R^(a) and R^(b) together form a group of formula

wherein Z′ is N or CR″ ‘, wherein 0 or 1 Z’ is N, X is O, S, NR⁷⁵ orCR⁷³R⁷⁴; R′″ is C₁-C₈alkyl and a′ is 0 or 1; or the radicals R¹¹, R¹⁴,R²⁰, R²¹, R²², R²³ and R²⁴ are—in each case—independently of each othera C₁-C₁₈alkyl group, which can optionally be substituted by at least onesubstituent E and/or interrupted by D; a C₃-C₁₂cycloalkyl group, whichcan optionally be substituted by at least one substituent E; aheterocycloalkyl group comprising 3 to 6 ring atoms, interrupted by atleast one heteroatom selected from —O—, —S— and —NR⁶⁵—, optionallybearing at least one substituent E; a C₆-C₁₄aryl group, which canoptionally be substituted by one or two groups G; a heteroaryl groupcomprising 3 to 11 ring atoms, which can optionally be substituted byone or two groups G; or a —NR⁶⁵-phenyl group, which can optionally besubstituted by one or two groups G; or in the case of X-1, X-2, X-3,X-31, X-34, X-35, X-36, X-37 and X-38 CN; or two adjacent radicals R¹¹or two adjacent radicals R¹⁴ form together a group

wherein A²¹, A^(21′), A²², A^(22′), A²³, A^(23′), A^(24′) and A²⁴ areindependently of each other hydrogen, a C₁-C₄alkyl group, aC₃-C₆cycloalkyl group, or a fluoroC₁-C₄alkyl group; or R²⁵ is CH₃ orethyl or iso-propyl; R²⁶ is a phenyl group, which can optionally besubstituted by one or two groups selected from CF₃ and C₁-C₈alkyl; orR²⁶ is CH₃; or iso-propyl; D is —S—, —O—, or —NR⁶⁵—; E is —OR⁶⁹, —CN,CF₃, C₁-C₈alkyl or F; G is —OR⁶⁹, —CN, CF₃ or C₁-C₈alkyl; R⁶⁵ is aphenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—; R⁶⁹ is a phenyl group, which canoptionally be substituted by one or two C₁-C₈alkyl groups; anunsubstituted C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—; and A¹ is C₆-C₁₀aryl; or two adjacent groups A^(l)together form a group

wherein R^(f), R^(g), R^(h) and R^(i) are independently of each otherhydrogen or C₁-C₈alkyl; Q¹ and Q² are independently of each otherhydrogen, C₁-C₁₈alkyl, or C₆-C₁₈aryl; w and x are independently of eachother 0, 1 or 2; z is 0, 1, 2 or 3; y, y′, y″, u, and v areindependently of each other 0, 1 or 2; y′″ is 0 or 1; p, q, r, s, t, t′,and t″ are independently of each other 0, 1, 2, 3 or 4; and r′ is 0, 1,or
 2. 12. The metal carbene complex according to claim 1, wherein themetal is Ir.
 13. The metal carbene complex according to claim 12,selected from the group consisting of formulae IIa, IIb, IIc, IId, IIe,IIf, IIg, and IIh;

wherein R¹, R², R³ and R⁴ are independently of each other—in eachcase—hydrogen; a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; a C₃-C₆cycloalkylgroup, which can optionally be substituted by at least one substituentE; or a phenyl group, which can optionally be substituted by one or twogroups G; R⁵ and R⁶ are independently of each other—in eachcase—hydrogen; a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G; R⁸ and R⁹ are independently of eachother hydrogen; a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G; D is —S— or —O—; E is —OR⁶⁹, —CN,CF₃, C₁-C₈alkyl or F; G is —OR⁶⁹, —CN, CF₃ or C₁-C₈alkyl; R⁶⁹ is aphenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkylgroup, which is interrupted by —O—; L is a monoanionic bidentate ligand;m is 1, 2, or 3; o is 0, 1, or 2; and the sum of m+o is 3; wherein wheno=2, the ligands L may be the same or different; and when m is 2 or 3,the m carbene ligands may be the same or different.
 14. The metalcarbene complex according to claim 13, selected from the groupconsisting of formulae II-1, II-2, II-3, II-4, II-5, II-6, II-7, II-8,II-9, II-10, II-11, II-12, II-13, II-14, II-15, II-16, II-17, II-18,II-19, II-20, II-21, II-22, II-23, II-24, II-25, II-26, II-27, II-28,II-29, II-30, II-31, II-32, II-33, II-34, II-35, II-36, II-37, II-38,II-39, II-40, II-41, II-42, II-43, II-44, II-45, II-46, II-47, II-48,II-49, II-50, II-51, II-52, II-53, II-54, II-55, II-56, II-57, II-58,II-59, II-60, II-61, II-62, II-63, II-64, II-65, II-66, II-67, II-68,II-69, II-70, II-71, II-72, II-73, and II-74;

wherein R¹, R², R³ and R⁴ are independently of each other—in eachcase—hydrogen, a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; a C₃-C₆cycloalkylgroup, which can optionally be substituted by at least one substituentE; or a phenyl group, which can optionally be substituted by one or twogroups G; R⁵ and R⁶ are independently of each other—in eachcase—hydrogen, a C₁-C₈alkyl group, which can optionally be substitutedby at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G; R⁸ and R⁹ are independently of eachother—in each case—hydrogen, a C₁-C₈alkyl group, which can optionally besubstituted by at least one substituent E and/or interrupted by D; or aC₃-C₆cycloalkyl group, which can optionally be substituted by at leastone substituent E; or a phenyl group, which can optionally besubstituted by one or two groups G; D is —S— or —O—; E is —OR⁶⁹, —CN,CF₃, C₁-C₈alkyl or F; G is —OR⁶⁹, —CN, CF₃ or C₁-C₈alkyl; R⁶⁹ is aphenyl group, which can optionally be substituted by one or twoC₁-C₈alkyl groups; an unsubstituted C₁-C₈alkyl group; or a C₁-C₈alkylgroup, which is interrupted by —O—; m is 2 or 1; wherein when m is 2,the two ligands are identical or different; o is 1 or 2; wherein when ois 2, the two ligands are identical or different; and the sum of m+o is3.
 15. An organic electronic device, comprising at least one metalcarbene complex of claim
 1. 16. The organic electronic device accordingto claim 15, wherein the organic electronic device is selected from anorganic light-emitting diode (OLED), an organic photovoltaic cell (OPV),an organic field-effect transistor (OFET) and a light-emittingelectrochemical cell (LEEC).
 17. A light-emitting layer comprising atleast one metal carbene complex according to claim
 1. 18. Thelight-emitting layer according to claim 17, comprising at least onemetal carbene complex of claim 1 and at least one host material.
 19. Anapparatus selected from the group consisting of a stationary visualdisplay unit; an illumination unit; a keyboard; an item of clothing;furniture; and wallpaper, wherein the apparatus comprises the organicelectronic device according to claim
 15. 20. A device selected from thegroup consisting of an electrophotographic photoreceptor, aphotoelectric converter, an organic solar cell (organic photovoltaic), aswitching element, an organic light emitting field effect transistor(OLEFET), an image sensor, a dye laser, and an electroluminescentdevice, wherein the device comprises the metal carbene complex ofclaim
 1. 21. A process for preparing a metal carbene complex accordingto claim 1, wherein the process comprises the step of contactingsuitable compounds comprising Ir with appropriate ligands or ligandprecursors.
 22. A process for preparing a metal carbene complexaccording to claim 1, comprising at least one ligand of formula (I′)

wherein: R^(5′) is a C₁-C₁₈alkyl group, which can optionally besubstituted by at least one substituent E and/or interrupted by D; aC₃-C₁₂cycloalkyl group, which can optionally be substituted by at leastone substituent E; a C₆-C₁₄aryl group, which can optionally besubstituted by at least one substituent G; a —N(C₆-C₁₄aryl)₂ group,which can optionally be substituted by at least one substituent G; or aheteroaryl group comprising 3 to 11 ring atoms, which can optionally besubstituted by at least one substituent G, interrupted by at least oneof O, S and N; comprising the step of reacting a metal carbene complexcomprising at least one ligand of formula (III)

with a compound of formula (IV) corresponding to the respectiveY-substituted residue R^(5′): R^(5′)—Y (IV) wherein X¹ is Cl, Br, or I;Y is —B(OH)₂, —B(OY¹)₂,

wherein Y¹ is a C₁-C₁₀alkyl group and Y² is independently in eachoccurrence a C₂-C₁₀alkylene group, such as —CY³Y⁴—CY⁵Y⁶—, or—CY⁷Y⁸—CY⁹Y¹⁰—CY¹¹Y¹²—, wherein Y³, Y⁴, Y⁵, Y⁶, Y⁷, Y⁸, Y⁹, Y¹⁰, Y¹¹ andY¹² are independently of each other hydrogen, or a C₁-C₁₀alkyl group,and Y¹³ and Y¹⁴ are independently of each other hydrogen, or aC₁-C₁₀alkyl group; or Y is —SnR³⁰⁷R³⁰⁸ R³⁰⁹, wherein R³⁰⁷, R³⁰⁸ and R³⁰⁹are identical or different and are hydrogen or C₁-C₆alkyl, wherein tworadicals optionally form a common ring and these radicals are optionallybranched or unbranched; ZnR³¹⁰R³¹¹, wherein R³¹⁰ is halogen and R³¹¹ isa C₁-C₁₀alkyl group, a C₆-C₁₂aryl group, or C₁-C₁₀alkenyl group; orSiR³¹²R³¹³R³¹⁴, wherein R³¹², R³¹³ and R³¹⁴ are identical or differentand are halogen or C₁-C₆alkyl, and wherein the metal is selected from Irand Pt.
 23. The metal carbene complex according to claim 1, wherein R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R²⁷ and R²⁹ are hydrogen.
 24. The metalcarbene complex according to claim 1, wherein the metal carbene complexhas one of the following formulae: